I am using Travelify theme and I am having some trouble restricting the characters in the comment section (textarea) or where the name or mail goes into the input tags.
I read some articles about changing the core files from
post.php / post-formats.php / formatting.php , for changing the
preg_match function and only allow
a-zA-Z0-9 and some other like
.,? characters or others to be used.And i would also like to add a text that appears that dosen't allow special characters.
I know that is not the best practice to change the core files, but some times it can help you.