diff --git a/sql/swad.sql b/sql/swad.sql
index cadd30e9..7bbb04c7 100644
--- a/sql/swad.sql
+++ b/sql/swad.sql
@@ -1087,7 +1087,7 @@ CREATE TABLE IF NOT EXISTS tst_answers (
 	Answer TEXT NOT NULL,
         Feedback TEXT NOT NULL,
 	ImageName VARCHAR(43) NOT NULL,
-        ImageTitle VARCHAR(255) NOT NULL,
+        ImageTitle VARCHAR(2047) NOT NULL,
         ImageURL VARCHAR(255) NOT NULL,
 	Correct ENUM('N','Y') NOT NULL,
 	INDEX(QstCod));
@@ -1147,7 +1147,7 @@ CREATE TABLE IF NOT EXISTS tst_questions (
 	Stem TEXT NOT NULL,
 	Feedback TEXT NOT NULL,
 	ImageName VARCHAR(43) NOT NULL,
-        ImageTitle VARCHAR(255) NOT NULL,
+        ImageTitle VARCHAR(2047) NOT NULL,
         ImageURL VARCHAR(255) NOT NULL,
 	NumHits INT NOT NULL DEFAULT 0,
 	NumHitsNotBlank INT NOT NULL DEFAULT 0,
@@ -1170,11 +1170,10 @@ CREATE TABLE IF NOT EXISTS tst_tags (
 	TagCod INT NOT NULL AUTO_INCREMENT,
 	CrsCod INT NOT NULL DEFAULT -1,
 	ChangeTime DATETIME NOT NULL,
-	TagTxt VARCHAR(255) NOT NULL,
+	TagTxt VARCHAR(2047) NOT NULL,
 	TagHidden ENUM('N','Y') NOT NULL,
 	UNIQUE INDEX(TagCod),
-	INDEX(CrsCod,ChangeTime),
-	INDEX(TagTxt));
+	INDEX(CrsCod,ChangeTime));
 --
 -- Table usr_banned: stores users banned for ranking
 --
diff --git a/swad_changelog.h b/swad_changelog.h
index 5f7405dd..1920ac23 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -209,13 +209,26 @@
 /****************************** Public constants *****************************/
 /*****************************************************************************/
 
-#define Log_PLATFORM_VERSION	"SWAD 16.155.26 (2017-03-13)"
+#define Log_PLATFORM_VERSION	"SWAD 16.155.27 (2017-03-13)"
 #define CSS_FILE		"swad16.147.css"
 #define JS_FILE			"swad16.144.js"
 
 // Number of lines (includes comments but not blank lines) has been got with the following command:
 // nl swad*.c swad*.h css/swad*.css py/swad*.py js/swad*.js soap/swad*?.h sql/swad*.sql | tail -1
 /*
+        Version 16.155.27:Mar 13, 2017	Adjusting size of database fields. (217038 lines)
+					4 changes necessary in database.
+ALTER TABLE tst_answers CHANGE COLUMN ImageTitle ImageTitle VARCHAR(2047) NOT NULL;
+ALTER TABLE tst_questions CHANGE COLUMN ImageTitle ImageTitle VARCHAR(2047) NOT NULL;
+DROP INDEX TagTxt ON tst_tags;
+ALTER TABLE tst_tags CHANGE COLUMN TagTxt TagTxt VARCHAR(2047) NOT NULL;
+
+   DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_tags ("
+			"TagCod INT NOT NULL AUTO_INCREMENT,"
+			"CrsCod INT NOT NULL DEFAULT -1,"
+			"ChangeTime DATETIME NOT NULL,"
+			"TagTxt VARCHAR(2047) NOT NULL,"	// Tst_MAX_BYTES_TAG
+
         Version 16.155.26:Mar 13, 2017	Adjusting size of database fields. (217009 lines)
 					3 changes necessary in database:
 ALTER TABLE timetable_crs CHANGE COLUMN Place Place VARCHAR(511) NOT NULL;
diff --git a/swad_database.c b/swad_database.c
index f2a09a7d..70014378 100644
--- a/swad_database.c
+++ b/swad_database.c
@@ -2303,22 +2303,22 @@ mysql> DESCRIBE tst_answers;
 | Answer     | text          | NO   |     | NULL    |       |
 | Feedback   | text          | NO   |     | NULL    |       |
 | ImageName  | varchar(43)   | NO   |     | NULL    |       |
-| ImageTitle | varchar(255)  | NO   |     | NULL    |       |
+| ImageTitle | varchar(2047) | NO   |     | NULL    |       |
 | ImageURL   | varchar(255)  | NO   |     | NULL    |       |
 | Correct    | enum('N','Y') | NO   |     | NULL    |       |
 +------------+---------------+------+-----+---------+-------+
-8 rows in set (0.01 sec)
+8 rows in set (0,00 sec)
 */
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_answers ("
-                   "QstCod INT NOT NULL,"
-                   "AnsInd TINYINT NOT NULL,"
-                   "Answer TEXT NOT NULL,"
-                   "Feedback TEXT NOT NULL,"
-                   "ImageName VARCHAR(43) NOT NULL,"
-                   "ImageTitle VARCHAR(255) NOT NULL,"
-                   "ImageURL VARCHAR(255) NOT NULL,"
-                   "Correct ENUM('N','Y') NOT NULL,"
-                   "INDEX(QstCod))");
+			"QstCod INT NOT NULL,"
+			"AnsInd TINYINT NOT NULL,"
+			"Answer TEXT NOT NULL,"			// Tst_MAX_BYTES_ANSWER_OR_FEEDBACK
+			"Feedback TEXT NOT NULL,"		// Tst_MAX_BYTES_ANSWER_OR_FEEDBACK
+			"ImageName VARCHAR(43) NOT NULL,"	// Img_BYTES_NAME
+			"ImageTitle VARCHAR(2047) NOT NULL,"	// Img_MAX_BYTES_TITLE
+			"ImageURL VARCHAR(255) NOT NULL,"	// Cns_MAX_BYTES_WWW
+			"Correct ENUM('N','Y') NOT NULL,"
+		   "INDEX(QstCod))");
 
    /***** Table tst_config *****/
 /*
@@ -2337,14 +2337,14 @@ mysql> DESCRIBE tst_config;
 7 rows in set (0,00 sec)
 */
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_config ("
-                   "CrsCod INT NOT NULL DEFAULT -1,"
-                   "Pluggable ENUM('unknown','N','Y') NOT NULL DEFAULT 'unknown',"
-                   "Min INT NOT NULL,"
-                   "Def INT NOT NULL,"
-                   "Max INT NOT NULL,"
-                   "MinTimeNxtTstPerQst INT NOT NULL DEFAULT 0,"
-                   "Feedback ENUM('nothing','total_result','each_result','each_good_bad','full_feedback') NOT NULL,"
-                   "UNIQUE INDEX(CrsCod))");
+			"CrsCod INT NOT NULL DEFAULT -1,"
+			"Pluggable ENUM('unknown','N','Y') NOT NULL DEFAULT 'unknown',"
+			"Min INT NOT NULL,"
+			"Def INT NOT NULL,"
+			"Max INT NOT NULL,"
+			"MinTimeNxtTstPerQst INT NOT NULL DEFAULT 0,"
+			"Feedback ENUM('nothing','total_result','each_result','each_good_bad','full_feedback') NOT NULL,"
+		   "UNIQUE INDEX(CrsCod))");
 
 /***** Table tst_exam_questions *****/
 /*
@@ -2362,13 +2362,13 @@ mysql> DESCRIBE tst_exam_questions;
 6 rows in set (0.00 sec)
 */
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_exam_questions ("
-                   "TstCod INT NOT NULL,"
-                   "QstCod INT NOT NULL,"
-                   "QstInd INT NOT NULL,"
-                   "Score DOUBLE PRECISION NOT NULL DEFAULT 0,"
-                   "Indexes TEXT NOT NULL,"
-                   "Answers TEXT NOT NULL,"
-                   "INDEX(TstCod,QstCod))");
+			"TstCod INT NOT NULL,"
+			"QstCod INT NOT NULL,"
+			"QstInd INT NOT NULL,"
+			"Score DOUBLE PRECISION NOT NULL DEFAULT 0,"
+			"Indexes TEXT NOT NULL,"	// Tst_MAX_BYTES_INDEXES_ONE_QST
+			"Answers TEXT NOT NULL,"	// Tst_MAX_BYTES_ANSWERS_ONE_QST
+		   "INDEX(TstCod,QstCod))");
 
    /***** Table tst_exams *****/
 /*
@@ -2388,16 +2388,16 @@ mysql> DESCRIBE tst_exams;
 8 rows in set (0.05 sec)
 */
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_exams ("
-                   "TstCod INT NOT NULL AUTO_INCREMENT,"
-                   "CrsCod INT NOT NULL,"
-                   "UsrCod INT NOT NULL,"
-                   "AllowTeachers ENUM('N','Y') NOT NULL DEFAULT 'N',"
-                   "TstTime DATETIME NOT NULL,"
-                   "NumQsts INT NOT NULL DEFAULT 0,"
-                   "NumQstsNotBlank INT NOT NULL DEFAULT 0,"
-                   "Score DOUBLE PRECISION NOT NULL DEFAULT 0,"
-                   "UNIQUE INDEX(TstCod),"
-                   "INDEX(CrsCod,UsrCod))");
+			"TstCod INT NOT NULL AUTO_INCREMENT,"
+			"CrsCod INT NOT NULL,"
+			"UsrCod INT NOT NULL,"
+			"AllowTeachers ENUM('N','Y') NOT NULL DEFAULT 'N',"
+			"TstTime DATETIME NOT NULL,"
+			"NumQsts INT NOT NULL DEFAULT 0,"
+			"NumQstsNotBlank INT NOT NULL DEFAULT 0,"
+			"Score DOUBLE PRECISION NOT NULL DEFAULT 0,"
+		   "UNIQUE INDEX(TstCod),"
+		   "INDEX(CrsCod,UsrCod))");
 
    /***** Table tst_question_tags *****/
 /*
@@ -2412,10 +2412,10 @@ mysql> DESCRIBE tst_question_tags;
 3 rows in set (0.00 sec)
 */
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_question_tags ("
-                   "QstCod INT NOT NULL,"
-                   "TagCod INT NOT NULL,"
-                   "TagInd TINYINT NOT NULL,"
-                   "UNIQUE INDEX(QstCod,TagCod))");
+			"QstCod INT NOT NULL,"
+			"TagCod INT NOT NULL,"
+			"TagInd TINYINT NOT NULL,"
+		   "UNIQUE INDEX(QstCod,TagCod))");
 
    /***** Table tst_questions *****/
 /*
@@ -2431,29 +2431,30 @@ mysql> DESCRIBE tst_questions;
 | Stem            | text                                                                      | NO   |     | NULL    |                |
 | Feedback        | text                                                                      | NO   |     | NULL    |                |
 | ImageName       | varchar(43)                                                               | NO   |     | NULL    |                |
-| ImageTitle      | varchar(255)                                                              | NO   |     | NULL    |                |
+| ImageTitle      | varchar(2047)                                                             | NO   |     | NULL    |                |
 | ImageURL        | varchar(255)                                                              | NO   |     | NULL    |                |
 | NumHits         | int(11)                                                                   | NO   |     | 0       |                |
 | NumHitsNotBlank | int(11)                                                                   | NO   |     | 0       |                |
 | Score           | double                                                                    | NO   |     | 0       |                |
 +-----------------+---------------------------------------------------------------------------+------+-----+---------+----------------+
-13 rows in set (0.00 sec)
+13 rows in set (0,00 sec)
 */
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_questions ("
-                   "QstCod INT NOT NULL AUTO_INCREMENT,"
-                   "CrsCod INT NOT NULL DEFAULT -1,"
-                   "EditTime DATETIME NOT NULL,"
-                   "AnsType ENUM ('int','float','true_false','unique_choice','multiple_choice','text') NOT NULL,"
-                   "Shuffle ENUM('N','Y') NOT NULL,"
-                   "Stem TEXT NOT NULL,"
-                   "Feedback TEXT NOT NULL,"
-                   "ImageName VARCHAR(43) NOT NULL,"
-                   "ImageTitle VARCHAR(255) NOT NULL,"
-                   "NumHits INT NOT NULL DEFAULT 0,"
-                   "NumHitsNotBlank INT NOT NULL DEFAULT 0,"
-                   "Score DOUBLE PRECISION NOT NULL DEFAULT 0,"
-                   "UNIQUE INDEX(QstCod),"
-                   "INDEX(CrsCod,EditTime))");
+			"QstCod INT NOT NULL AUTO_INCREMENT,"
+			"CrsCod INT NOT NULL DEFAULT -1,"
+			"EditTime DATETIME NOT NULL,"
+			"AnsType ENUM ('int','float','true_false','unique_choice','multiple_choice','text') NOT NULL,"
+			"Shuffle ENUM('N','Y') NOT NULL,"
+			"Stem TEXT NOT NULL,"			// Cns_MAX_BYTES_TEXT
+			"Feedback TEXT NOT NULL,"		// Cns_MAX_BYTES_TEXT
+			"ImageName VARCHAR(43) NOT NULL,"	// Img_BYTES_NAME
+			"ImageTitle VARCHAR(2047) NOT NULL,"	// Img_MAX_BYTES_TITLE
+			"ImageURL VARCHAR(255) NOT NULL,"	// Cns_MAX_BYTES_WWW
+			"NumHits INT NOT NULL DEFAULT 0,"
+			"NumHitsNotBlank INT NOT NULL DEFAULT 0,"
+			"Score DOUBLE PRECISION NOT NULL DEFAULT 0,"
+		   "UNIQUE INDEX(QstCod),"
+		   "INDEX(CrsCod,EditTime))");
 
    /***** Table tst_status *****/
 /*
@@ -2469,11 +2470,11 @@ mysql> DESCRIBE tst_status;
 4 rows in set (0.00 sec)
 */
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_status ("
-                   "SessionId CHAR(43) NOT NULL,"
-                   "CrsCod INT NOT NULL,"
-                   "NumTst INT NOT NULL,"
-                   "Status TINYINT NOT NULL,"
-                   "UNIQUE INDEX(SessionId,CrsCod,NumTst))");
+			"SessionId CHAR(43) NOT NULL,"
+			"CrsCod INT NOT NULL,"
+			"NumTst INT NOT NULL,"
+			"Status TINYINT NOT NULL,"
+		   "UNIQUE INDEX(SessionId,CrsCod,NumTst))");
 
    /***** Table tst_tags *****/
 /*
@@ -2484,21 +2485,20 @@ mysql> DESCRIBE tst_tags;
 | TagCod     | int(11)       | NO   | PRI | NULL    | auto_increment |
 | CrsCod     | int(11)       | NO   | MUL | -1      |                |
 | ChangeTime | datetime      | NO   |     | NULL    |                |
-| TagTxt     | varchar(255)  | NO   | MUL | NULL    |                |
+| TagTxt     | varchar(2047) | NO   |     | NULL    |                |
 | TagHidden  | enum('N','Y') | NO   |     | NULL    |                |
 +------------+---------------+------+-----+---------+----------------+
-5 rows in set (0.00 sec)
+5 rows in set (0,00 sec)
 */
 // CrsCod is redundant for speed in querys
    DB_CreateTable ("CREATE TABLE IF NOT EXISTS tst_tags ("
-                   "TagCod INT NOT NULL AUTO_INCREMENT,"
-                   "CrsCod INT NOT NULL DEFAULT -1,"
-                   "ChangeTime DATETIME NOT NULL,"
-                   "TagTxt VARCHAR(255) NOT NULL,"
-                   "TagHidden ENUM('N','Y') NOT NULL,"
-                   "UNIQUE INDEX(TagCod),"
-                   "INDEX(CrsCod,ChangeTime),"
-                   "INDEX(TagTxt))");
+			"TagCod INT NOT NULL AUTO_INCREMENT,"
+			"CrsCod INT NOT NULL DEFAULT -1,"
+			"ChangeTime DATETIME NOT NULL,"
+			"TagTxt VARCHAR(2047) NOT NULL,"	// Tst_MAX_BYTES_TAG
+			"TagHidden ENUM('N','Y') NOT NULL,"
+		   "UNIQUE INDEX(TagCod),"
+		   "INDEX(CrsCod,ChangeTime))");
 
    /***** Table usr_banned *****/
 /*
diff --git a/swad_global.h b/swad_global.h
index d6feac4f..a2230556 100644
--- a/swad_global.h
+++ b/swad_global.h
@@ -653,8 +653,8 @@ struct Globals
       Tst_AnswerType_t AnswerType;
       unsigned NumQsts;
       long QstCodes[Tst_MAX_QUESTIONS_PER_TEST];	// Codes of the sent/received questions in a test
-      char StrIndexesOneQst[Tst_MAX_QUESTIONS_PER_TEST][Tst_MAX_SIZE_INDEXES_ONE_QST + 1];	// 0 1 2 3, 3 0 2 1, etc.
-      char StrAnswersOneQst[Tst_MAX_QUESTIONS_PER_TEST][Tst_MAX_SIZE_ANSWERS_ONE_QST + 1];	// Answers selected by user
+      char StrIndexesOneQst[Tst_MAX_QUESTIONS_PER_TEST][Tst_MAX_BYTES_INDEXES_ONE_QST + 1];	// 0 1 2 3, 3 0 2 1, etc.
+      char StrAnswersOneQst[Tst_MAX_QUESTIONS_PER_TEST][Tst_MAX_BYTES_ANSWERS_ONE_QST + 1];	// Answers selected by user
       bool AllowTeachers;	// Can teachers of this course see the test result?
       bool AllAnsTypes;
       struct
diff --git a/swad_test.c b/swad_test.c
index 6d66d539..d471dd5b 100644
--- a/swad_test.c
+++ b/swad_test.c
@@ -592,11 +592,13 @@ static void Tst_GetQuestionsAndAnswersFromForm (void)
 
       /* Get indexes for this question */
       sprintf (StrQstIndOrAns,"Ind%06u",NumQst);
-      Par_GetParMultiToText (StrQstIndOrAns,Gbl.Test.StrIndexesOneQst[NumQst],Tst_MAX_SIZE_INDEXES_ONE_QST);  /* If choice ==> "0", "1", "2",... */
+      Par_GetParMultiToText (StrQstIndOrAns,Gbl.Test.StrIndexesOneQst[NumQst],
+                             Tst_MAX_BYTES_INDEXES_ONE_QST);  /* If choice ==> "0", "1", "2",... */
 
       /* Get answers selected by user for this question */
       sprintf (StrQstIndOrAns,"Ans%06u",NumQst);
-      Par_GetParMultiToText (StrQstIndOrAns,Gbl.Test.StrAnswersOneQst[NumQst],Tst_MAX_SIZE_ANSWERS_ONE_QST);  /* If answer type == T/F ==> " ", "T", "F"; if choice ==> "0", "2",... */
+      Par_GetParMultiToText (StrQstIndOrAns,Gbl.Test.StrAnswersOneQst[NumQst],
+                             Tst_MAX_BYTES_ANSWERS_ONE_QST);  /* If answer type == T/F ==> " ", "T", "F"; if choice ==> "0", "2",... */
      }
   }
 
@@ -691,7 +693,7 @@ static bool Tst_CheckIfNextTstAllowed (void)
 
 static void Tst_SetTstStatus (unsigned NumTst,Tst_Status_t TstStatus)
   {
-   char Query[512 + Ses_BYTES_SESSION_ID];
+   char Query[256 + Ses_BYTES_SESSION_ID];
 
    /***** Delete old status from expired sessions *****/
    sprintf (Query,"DELETE FROM tst_status"
@@ -703,7 +705,8 @@ static void Tst_SetTstStatus (unsigned NumTst,Tst_Status_t TstStatus)
 	          " (SessionId,CrsCod,NumTst,Status)"
 	          " VALUES"
 	          " ('%s','%ld','%u','%u')",
-            Gbl.Session.Id,Gbl.CurrentCrs.Crs.CrsCod,NumTst,(unsigned) TstStatus);
+            Gbl.Session.Id,Gbl.CurrentCrs.Crs.CrsCod,
+            NumTst,(unsigned) TstStatus);
    DB_QueryREPLACE (Query,"can not update status of test");
   }
 
@@ -713,7 +716,7 @@ static void Tst_SetTstStatus (unsigned NumTst,Tst_Status_t TstStatus)
 
 static Tst_Status_t Tst_GetTstStatus (unsigned NumTst)
   {
-   char Query[512];
+   char Query[256 + Ses_BYTES_SESSION_ID];
    MYSQL_RES *mysql_res;
    MYSQL_ROW row;
    unsigned long NumRows;
@@ -748,7 +751,7 @@ static Tst_Status_t Tst_GetTstStatus (unsigned NumTst)
 
 static unsigned Tst_GetNumAccessesTst (void)
   {
-   char Query[512];
+   char Query[256];
    MYSQL_RES *mysql_res;
    MYSQL_ROW row;
    unsigned long NumRows;
@@ -758,7 +761,7 @@ static unsigned Tst_GetNumAccessesTst (void)
      {
       /***** Get number of hits to test from database *****/
       sprintf (Query,"SELECT NumAccTst FROM crs_usr"
-                     " WHERE CrsCod='%ld' AND UsrCod='%ld'",
+	             " WHERE CrsCod='%ld' AND UsrCod='%ld'",
                Gbl.CurrentCrs.Crs.CrsCod,Gbl.Usrs.Me.UsrDat.UsrCod);
       NumRows = DB_QuerySELECT (Query,&mysql_res,"can not get number of hits to test");
 
@@ -1188,7 +1191,8 @@ static void Tst_UpdateScoreQst (long QstCod,float ScoreThisQst,bool AnswerIsNotB
    Str_SetDecimalPointToUS ();	// To print the floating point as a dot
    if (AnswerIsNotBlank)
       sprintf (Query,"UPDATE tst_questions"
-	             " SET NumHits=NumHits+1,NumHitsNotBlank=NumHitsNotBlank+1,Score=Score+(%lf)"
+	             " SET NumHits=NumHits+1,NumHitsNotBlank=NumHitsNotBlank+1,"
+	             "Score=Score+(%lf)"
                      " WHERE QstCod='%ld'",
                ScoreThisQst,QstCod);
    else	// The answer is blank
@@ -1206,7 +1210,7 @@ static void Tst_UpdateScoreQst (long QstCod,float ScoreThisQst,bool AnswerIsNotB
 
 static void Tst_UpdateMyNumAccessTst (unsigned NumAccessesTst)
   {
-   char Query[512];
+   char Query[256];
 
    /***** Update my number of accesses to test in this course *****/
    sprintf (Query,"UPDATE crs_usr SET NumAccTst='%u'"
@@ -1222,7 +1226,7 @@ static void Tst_UpdateMyNumAccessTst (unsigned NumAccessesTst)
 
 static void Tst_UpdateLastAccTst (void)
   {
-   char Query[512];
+   char Query[256];
 
    /***** Update date-time and number of questions of this test *****/
    sprintf (Query,"UPDATE crs_usr SET LastAccTst=NOW(),NumQstsLastTst='%u'"
@@ -1499,26 +1503,30 @@ void Tst_RenameTag (void)
 	    sprintf (Query,"DROP TEMPORARY TABLE IF EXISTS tst_question_tags_tmp");
 	    if (mysql_query (&Gbl.mysql,Query))
 	       DB_ExitOnMySQLError ("can not remove temporary table");
-	    sprintf (Query,"CREATE TEMPORARY TABLE tst_question_tags_tmp ENGINE=MEMORY"
-			   " SELECT QstCod FROM tst_question_tags WHERE TagCod='%ld'",
+	    sprintf (Query,"CREATE TEMPORARY TABLE tst_question_tags_tmp"
+		           " ENGINE=MEMORY"
+			   " SELECT QstCod FROM tst_question_tags"
+			   " WHERE TagCod='%ld'",
 		     ExistingTagCod);
 	    if (mysql_query (&Gbl.mysql,Query))
 	       DB_ExitOnMySQLError ("can not create temporary table");
 
 	    /* Remove old tag in questions where it would be repeated */
+	    // New tag existed for a question ==> delete old tag
 	    sprintf (Query,"DELETE FROM tst_question_tags"
 			   " WHERE TagCod='%ld'"
 			   " AND QstCod IN"
-			   " (SELECT QstCod FROM tst_question_tags_tmp)",	// New tag existed for a question ==> delete old tag
+			   " (SELECT QstCod FROM tst_question_tags_tmp)",
 		     OldTagCod);
 	    DB_QueryDELETE (Query,"can not remove a tag from some questions");
 
 	    /* Change old tag to new tag in questions where it would not be repeated */
+	    // New tag did not exist for a question ==> change old tag to new tag
 	    sprintf (Query,"UPDATE tst_question_tags"
 			   " SET TagCod='%ld'"
 			   " WHERE TagCod='%ld'"
 			   " AND QstCod NOT IN"
-			   " (SELECT QstCod FROM tst_question_tags_tmp)",	// New tag did not exist for a question ==> change old tag to new tag
+			   " (SELECT QstCod FROM tst_question_tags_tmp)",
 		     ExistingTagCod,
 		     OldTagCod);
 	    DB_QueryUPDATE (Query,"can not update a tag in some questions");
@@ -1562,7 +1570,7 @@ void Tst_RenameTag (void)
 
 static bool Tst_CheckIfCurrentCrsHasTestTags (void)
   {
-   char Query[512];
+   char Query[128];
 
    /***** Get available tags from database *****/
    sprintf (Query,"SELECT COUNT(*) FROM tst_tags WHERE CrsCod='%ld'",
@@ -1577,7 +1585,7 @@ static bool Tst_CheckIfCurrentCrsHasTestTags (void)
 
 static unsigned long Tst_GetAllTagsFromCurrentCrs (MYSQL_RES **mysql_res)
   {
-   char Query[512];
+   char Query[256];
 
    /***** Get available tags from database *****/
    sprintf (Query,"SELECT TagCod,TagTxt,TagHidden FROM tst_tags"
@@ -1593,7 +1601,7 @@ static unsigned long Tst_GetAllTagsFromCurrentCrs (MYSQL_RES **mysql_res)
 
 static unsigned long Tst_GetEnabledTagsFromThisCrs (MYSQL_RES **mysql_res)
   {
-   char Query[512];
+   char Query[256];
 
    /***** Get available not hidden tags from database *****/
    sprintf (Query,"SELECT TagCod,TagTxt FROM tst_tags"
@@ -1963,7 +1971,7 @@ static void Tst_PutInputFieldNumQst (const char *Field,const char *Label,
 
 static void Tst_GetConfigTstFromDB (void)
   {
-   char Query[512];
+   char Query[256];
    MYSQL_RES *mysql_res;
    MYSQL_ROW row;
    unsigned long NumRows;
@@ -2062,7 +2070,7 @@ void Tst_GetConfigFromRow (MYSQL_ROW row)
 
 bool Tst_CheckIfCourseHaveTestsAndPluggableIsUnknown (void)
   {
-   char Query[512];
+   char Query[128];
    MYSQL_RES *mysql_res;
    MYSQL_ROW row;
    unsigned long NumRows;
@@ -2302,26 +2310,31 @@ void Tst_ListQuestionsToEdit (void)
    unsigned long NumRows;
 
    /***** Get parameters, query the database and list the questions *****/
-   if (Tst_GetParamsTst ())							// Get parameters of the form
+   if (Tst_GetParamsTst ())	// Get parameters from the form
      {
-      if ((NumRows = Tst_GetQuestionsForEdit (&mysql_res)) != 0)		// Query database
+      if ((NumRows = Tst_GetQuestionsForEdit (&mysql_res)) != 0)	// Query database
         {
-	 /***** Buttons for edition *****/
+	 /* Buttons for edition */
          fprintf (Gbl.F.Out,"<div class=\"CONTEXT_MENU\">");
 	 if (Gbl.Test.XML.CreateXML)
-            TsI_CreateXML (NumRows,mysql_res);	// Create XML file for exporting questions and put a link to download it
+	    /* Create XML file for exporting questions
+	       and put a link to download it */
+            TsI_CreateXML (NumRows,mysql_res);
          else
-            TsI_PutFormToExportQuestions ();	// Button to export questions
+            /* Button to export questions */
+            TsI_PutFormToExportQuestions ();
 	 fprintf (Gbl.F.Out,"</div>");
 
-         Tst_ListOneOrMoreQuestionsToEdit (NumRows,mysql_res);			// Show the table with the questions
+	 /* Show the table with the questions */
+         Tst_ListOneOrMoreQuestionsToEdit (NumRows,mysql_res);
         }
 
       /***** Free structure that stores the query result *****/
       DB_FreeMySQLResult (&mysql_res);
      }
    else
-      Tst_ShowFormAskEditTsts ();						// Show the form again
+      /* Show the form again */
+      Tst_ShowFormAskEditTsts ();
 
    /***** Free memory used by the list of tags *****/
    Tst_FreeTagsList ();
@@ -3709,7 +3722,7 @@ static void Tst_WriteTextAnsViewTest (unsigned NumQst)
    /***** Write input field for the answer *****/
    fprintf (Gbl.F.Out,"<input type=\"text\" name=\"Ans%06u\""
 	              " size=\"40\" maxlength=\"%u\" value=\"\" />",
-            NumQst,Tst_MAX_SIZE_ANSWERS_ONE_QST);
+            NumQst,Tst_MAX_BYTES_ANSWERS_ONE_QST);
   }
 
 /*****************************************************************************/
@@ -3721,8 +3734,8 @@ static void Tst_WriteTextAnsAssessTest (unsigned NumQst,MYSQL_RES *mysql_res,
   {
    unsigned NumOpt;
    MYSQL_ROW row;
-   char TextAnsUsr[Tst_MAX_SIZE_ANSWERS_ONE_QST + 1];
-   char TextAnsOK[Tst_MAX_SIZE_ANSWERS_ONE_QST + 1];
+   char TextAnsUsr[Tst_MAX_BYTES_ANSWERS_ONE_QST + 1];
+   char TextAnsOK[Tst_MAX_BYTES_ANSWERS_ONE_QST + 1];
    bool Correct = false;
    /*
    row[ 0] AnsInd
@@ -3781,7 +3794,7 @@ static void Tst_WriteTextAnsAssessTest (unsigned NumQst,MYSQL_RES *mysql_res,
      {
       /* Filter the user answer */
       Str_Copy (TextAnsUsr,Gbl.Test.StrAnswersOneQst[NumQst],
-                Tst_MAX_SIZE_ANSWERS_ONE_QST);
+                Tst_MAX_BYTES_ANSWERS_ONE_QST);
 
       /* In order to compare student answer to stored answer,
 	 the text answers are stored avoiding two or more consecurive spaces */
@@ -3795,7 +3808,7 @@ static void Tst_WriteTextAnsAssessTest (unsigned NumQst,MYSQL_RES *mysql_res,
         {
          /* Filter this correct answer */
          Str_Copy (TextAnsOK,Gbl.Test.Answer.Options[NumOpt].Text,
-                   Tst_MAX_SIZE_ANSWERS_ONE_QST);
+                   Tst_MAX_BYTES_ANSWERS_ONE_QST);
          Str_ConvertToComparable (TextAnsOK);
 
          /* Check is user answer is correct */
@@ -4201,7 +4214,9 @@ unsigned long Tst_GetTagsQst (long QstCod,MYSQL_RES **mysql_res)
 
    /***** Get the tags of a question from database *****/
    sprintf (Query,"SELECT tst_tags.TagTxt FROM tst_question_tags,tst_tags"
-                  " WHERE tst_question_tags.QstCod='%ld' AND tst_question_tags.TagCod=tst_tags.TagCod AND tst_tags.CrsCod='%ld'"
+                  " WHERE tst_question_tags.QstCod='%ld'"
+                  " AND tst_question_tags.TagCod=tst_tags.TagCod"
+                  " AND tst_tags.CrsCod='%ld'"
                   " ORDER BY tst_question_tags.TagInd",
             QstCod,Gbl.CurrentCrs.Crs.CrsCod);
    return DB_QuerySELECT (Query,mysql_res,"can not get the tags of a question");
@@ -5286,7 +5301,7 @@ static void Tst_GetQstFromForm (char *Stem,char *Feedback)
    char TagStr[6 + 10 + 1];
    char AnsStr[6 + 10 + 1];
    char FbStr[5 + 10 + 1];
-   char StrMultiAns[Tst_MAX_SIZE_ANSWERS_ONE_QST + 1];
+   char StrMultiAns[Tst_MAX_BYTES_ANSWERS_ONE_QST + 1];
    char TF[1 + 1];	// (T)rue or (F)alse
    const char *Ptr;
    unsigned NumCorrectAns;
@@ -5417,7 +5432,7 @@ static void Tst_GetQstFromForm (char *Stem,char *Feedback)
            }
       	 else if (Gbl.Test.AnswerType == Tst_ANS_MULTIPLE_CHOICE)
            {
-	    Par_GetParMultiToText ("AnsMulti",StrMultiAns,Tst_MAX_SIZE_ANSWERS_ONE_QST);
+	    Par_GetParMultiToText ("AnsMulti",StrMultiAns,Tst_MAX_BYTES_ANSWERS_ONE_QST);
  	    Ptr = StrMultiAns;
             while (*Ptr)
               {
@@ -5895,7 +5910,7 @@ void Tst_RequestRemoveQst (void)
 void Tst_RemoveQst (void)
   {
    extern const char *Txt_Question_removed;
-   char Query[512];
+   char Query[256];
    bool EditingOnlyThisQst;
 
    /***** Get the question code *****/
@@ -5942,7 +5957,7 @@ void Tst_ChangeShuffleQst (void)
   {
    extern const char *Txt_The_answers_of_the_question_with_code_X_will_appear_shuffled;
    extern const char *Txt_The_answers_of_the_question_with_code_X_will_appear_without_shuffling;
-   char Query[512];
+   char Query[256];
    bool EditingOnlyThisQst;
    bool Shuffle;
 
@@ -6022,7 +6037,8 @@ static void Tst_InsertOrUpdateQstIntoDB (void)
                         Gbl.Test.Stem.Length +
                         Gbl.Test.Feedback.Length +
                         Img_BYTES_NAME +
-                        Img_MAX_BYTES_TITLE)) == NULL)
+                        Img_MAX_BYTES_TITLE +
+                        Cns_MAX_BYTES_WWW)) == NULL)
       Lay_ShowErrorAndExit ("Not enough memory to store database query.");
 
    if (Gbl.Test.QstCod < 0)	// It's a new question
@@ -6129,7 +6145,11 @@ static void Tst_InsertAnswersIntoDB (void)
    unsigned i;
 
    /***** Allocate space for query *****/
-   if ((Query = malloc (256 + Tst_MAX_BYTES_ANSWER_OR_FEEDBACK * 2)) == NULL)
+   if ((Query = malloc (256 +
+                        Tst_MAX_BYTES_ANSWER_OR_FEEDBACK * 2 +
+                        Img_BYTES_NAME +
+                        Img_MAX_BYTES_TITLE +
+                        Cns_MAX_BYTES_WWW)) == NULL)
       Lay_ShowErrorAndExit ("Not enough memory to store database query.");
 
    /***** Insert answers in the answers table *****/
@@ -6214,7 +6234,7 @@ static void Tst_InsertAnswersIntoDB (void)
 
 static void Tst_RemAnsFromQst (void)
   {
-   char Query[512];
+   char Query[128];
 
    /***** Remove answers *****/
    sprintf (Query,"DELETE FROM tst_answers WHERE QstCod='%ld'",
@@ -6228,7 +6248,7 @@ static void Tst_RemAnsFromQst (void)
 
 static void Tst_RemTagsFromQst (void)
   {
-   char Query[512];
+   char Query[128];
 
    /***** Remove tags *****/
    sprintf (Query,"DELETE FROM tst_question_tags WHERE QstCod='%ld'",
@@ -6242,7 +6262,7 @@ static void Tst_RemTagsFromQst (void)
 
 static void Tst_RemoveUnusedTagsFromCurrentCrs (void)
   {
-   char Query[1024];
+   char Query[512];
 
    /***** Remove unused tags from tst_tags *****/
    sprintf (Query,"DELETE FROM tst_tags"
@@ -6290,15 +6310,14 @@ static void Tst_RemoveImgFileFromStemOfQst (long CrsCod,long QstCod)
 
 static void Tst_RemoveAllImgFilesFromStemOfAllQstsInCrs (long CrsCod)
   {
-   char Query[256];
+   char Query[128];
    MYSQL_RES *mysql_res;
    MYSQL_ROW row;
    unsigned NumImages;
    unsigned NumImg;
 
    /***** Get names of images associated to stems of test questions from database *****/
-   sprintf (Query,"SELECT ImageName FROM tst_questions"
-		  " WHERE CrsCod='%ld'",
+   sprintf (Query,"SELECT ImageName FROM tst_questions WHERE CrsCod='%ld'",
 	    CrsCod);
    NumImages = (unsigned) DB_QuerySELECT (Query,&mysql_res,"can not get images");
 
@@ -7885,9 +7904,11 @@ static void Tst_GetTestResultDataByTstCod (long TstCod,time_t *TstTimeUTC,
 
 static void Tst_StoreOneTestResultQstInDB (long TstCod,long QstCod,unsigned NumQst,double Score)
   {
-   char Query[256 + Tst_MAX_SIZE_INDEXES_ONE_QST + Tst_MAX_SIZE_ANSWERS_ONE_QST];
-   char Indexes[Tst_MAX_SIZE_INDEXES_ONE_QST + 1];
-   char Answers[Tst_MAX_SIZE_ANSWERS_ONE_QST + 1];
+   char Query[256 +
+              Tst_MAX_BYTES_INDEXES_ONE_QST +
+              Tst_MAX_BYTES_ANSWERS_ONE_QST];
+   char Indexes[Tst_MAX_BYTES_INDEXES_ONE_QST + 1];
+   char Answers[Tst_MAX_BYTES_ANSWERS_ONE_QST + 1];
 
    /***** Replace each separator of multiple parameters by a comma *****/
    /* In database commas are used as separators instead of special chars */
@@ -7915,14 +7936,13 @@ static void Tst_StoreOneTestResultQstInDB (long TstCod,long QstCod,unsigned NumQ
 
 static void Tst_GetTestResultQuestionsFromDB (long TstCod)
   {
-   char Query[512];
+   char Query[256];
    MYSQL_RES *mysql_res;
    MYSQL_ROW row;
    unsigned NumQst;
 
    /***** Get questions of a test result from database *****/
-   sprintf (Query,"SELECT QstCod,Indexes,Answers"
-	          " FROM tst_exam_questions"
+   sprintf (Query,"SELECT QstCod,Indexes,Answers FROM tst_exam_questions"
                   " WHERE TstCod='%ld' ORDER BY QstInd",
             TstCod);
    Gbl.Test.NumQsts = (unsigned) DB_QuerySELECT (Query,&mysql_res,"can not get questions of a test result");
@@ -7940,11 +7960,11 @@ static void Tst_GetTestResultQuestionsFromDB (long TstCod)
 
       /* Get indexes for this question (row[1]) */
       Str_Copy (Gbl.Test.StrIndexesOneQst[NumQst],row[1],
-                Tst_MAX_SIZE_INDEXES_ONE_QST);
+                Tst_MAX_BYTES_INDEXES_ONE_QST);
 
       /* Get answers selected by user for this question (row[2]) */
       Str_Copy (Gbl.Test.StrAnswersOneQst[NumQst],row[2],
-                Tst_MAX_SIZE_ANSWERS_ONE_QST);
+                Tst_MAX_BYTES_ANSWERS_ONE_QST);
 
       /* Replace each comma by a separator of multiple parameters */
       /* In database commas are used as separators instead of special chars */
@@ -8017,8 +8037,7 @@ void Tst_RemoveCrsTestResults (long CrsCod)
    DB_QueryDELETE (Query,"can not remove test results made in a course");
 
    /***** Remove test results made in the course *****/
-   sprintf (Query,"DELETE FROM tst_exams"
-	          " WHERE CrsCod='%ld'",
+   sprintf (Query,"DELETE FROM tst_exams WHERE CrsCod='%ld'",
 	    CrsCod);
    DB_QueryDELETE (Query,"can not remove test results made in a course");
   }
diff --git a/swad_test.h b/swad_test.h
index 93046f0f..bd1d7464 100644
--- a/swad_test.h
+++ b/swad_test.h
@@ -40,8 +40,8 @@
 #define Tst_MAX_BYTES_TAG			((Tst_MAX_CHARS_TAG + 1) * Str_MAX_BYTES_PER_CHAR - 1)	// 2047
 
 #define Tst_MAX_OPTIONS_PER_QUESTION		  10
-#define Tst_MAX_SIZE_INDEXES_ONE_QST		(Tst_MAX_OPTIONS_PER_QUESTION * (10 + 1))
-#define Tst_MAX_SIZE_ANSWERS_ONE_QST		(Tst_MAX_OPTIONS_PER_QUESTION * (10 + 1))
+#define Tst_MAX_BYTES_INDEXES_ONE_QST		(Tst_MAX_OPTIONS_PER_QUESTION * (10 + 1))
+#define Tst_MAX_BYTES_ANSWERS_ONE_QST		(Tst_MAX_OPTIONS_PER_QUESTION * (10 + 1))
 
 #define Tst_MAX_CHARS_ANSWER_OR_FEEDBACK	(1024 - 1)	// 1023
 #define Tst_MAX_BYTES_ANSWER_OR_FEEDBACK	((Tst_MAX_CHARS_ANSWER_OR_FEEDBACK + 1) * Str_MAX_BYTES_PER_CHAR - 1)	// 16383