{{gender:}} is a very useful function to make templates like userboxes and user-related messages be more expressive, especially in some non-English languages. In Spanish for instance, the expression "This user is a doctor" is gender dependant, so you *must* say "[Este usuario|Esta usuaria] es un doctor".
{{gender:|Este usuario|Esta usuaria}} es un doctor.
Alternatively, a {{USERNAME}} variable would be a more general solution for username detection when used into user spaces. It could also be used in phrases like:
Hi {{USERNAME}}! instead of Hi {{PAGENAME}}!
Version: unspecified
Severity: enhancement