When the "genders" switch is enabled at Admin Panel -> Settings -> Switches, an option appears on the edit profile page for members to specify their gender. The gender options are male, female and transgender. When genders are on and the member has selected a gender, a small gender icon will appear by their posts. To show that icon elsewhere, use {MEMBERGENDERSYMBOL}. If you just want to display the gender as text, use {MEMBERGENDER}.