Custom System Error Messages

Hi Community,

I would like to know if I can add/edit an error system messages.

Currently, I use RETURN -1 and it gives "Account doesn't exist"
Also, If I use the return codes on sysmsg-uni.txt still the same message i get "Account doesn't exists"

Now, I would like to ask your help it is possible to add an error message on the RETURN or edit the existing error messages.

Thanks.

Yes it's possible and if you use SEARCH button you gonna find " HOW" And "WHERE" you have to go .

RETURN -1 will get a message "account doesn't exist".(no need to use RETURN)
Just set the status to whatever you desire. And edit the message on that equivalent code.
Ex.
I solve it by Set @[Only registered and activated users can see links. Click Here To Register...] = 1 (edit sysmsg code 10028 to any custom message)