Update description MultiForm

Documentation/Manual.rst

@@ -4353,16 +4353,32 @@ Action
 Multi Form
 ----------
 
-`Multi Forms` are like regular forms, but work on 'n' records at the same time.
+`Multi Forms` are like a regular with the difference that the shown FormElements are repeated for each selected record
+(defined by 'multiformSql').
 
-Image a form with 3 native FormElements, a statement `multiFormSql={{!SELECT p.id AS _id FROM Person AS p}}` and 20 records
-in table `Person`: QFQ will show a form with a table of 3 columns and 20 rows with FormElements, arranged in a table.
+The Form is shown as a table.
 
-* multiFormSql: A uniq column 'id' or '_id' is required. Columns
+* multiFormSql: Selects the primary record where the defined FormElements will work on.
 
+  * A uniq column 'id' or '_id' (not shown) is mandatory and has to reflect an existing record id in table `primary table`.
+  * Additional columns, defined in multiFormSql, will be shown in the same line, before the FormElements.
 
-Simple mode
 
+Simple
+======
+
+* The FormElement.name represents a column of the given primary table.
+* It's not possible to create new records.
+* Only existing records can be selected and edited in this mode.
+* Per multiFormSql row, the STORE_RECORD is filled with the whole record of the primary table, defined by `multiFormSql.id`.
+* The existing values of such FormElements are automatically loaded.
+* No further definition is required.
+
+Advanced
+========
+
+* The FormElement.name is not a column of the primary table.
+* The insert/update/delete of each non-primary table record has to be manually defined.
 
 
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