Should it be "user name" or "username? Maybe something new to standardize in our terminology list? koha-tmpl/intranet-tmpl/prog/en/includes/ill-batch-modal.inc:22
Koha/Database/Columns.pm: "userid" => __("Username"), Should be username I'd say.
I agree that it should be Username User name is less common and I usually see: username=userid/unique identifier user name= name of the user, there may be multiple users with the same name. https://www.merriam-webster.com/dictionary/username