this language string from editbasic.php contains a variable:
$ubbt_lang['CUSTOM_TITLE'] = "Custom Title (%%CHARS%% characters max)";

%%CHARS%% is not filled in and be blank all the time.

yes, this is a bug that i reported awhile back.

it's more than just a bug there, because the Custom Title length is used elsewhere. i know i posted the code change, because i have it working on my 7.3.1-SD.

right now, with 7.3.1 stock, you can have a Custom title that isn't actually even checked for length..

i believe it involves changing 3 source files and also getting rid of a $config variable that isn't even used anymore.. a misspelled one at that.. i think it was CUSTOM_TTITLE or the like before