Edit field - Type: Text - Options tab
Maximum entry length
In this field, you can define
the maximum amount of characters that may be entered. If you leave this
field blank, the maximum of 255 characters will be defined.
The edit field is not suitable for entering more characters.
Use the text area
instead for longer texts. If a user exceeds the maximum number
of characters, an error message will appear.
Restrict entry via regular expression
You can enter a regular expression that defines which characters may be
entered. Other characters will not be accepted.
The following regular expressions are possible:
exactly one lower case letter from a-z
0 to infinite letter from a-z
exactly one number between 0 and 9
exactly one character - one letter, number or underscore
a,b or c
not a,b or c
Following characters need to be escaped by a backslash: