Common gender is a gender in English. This gender has personal agential gender, but covers both masculine and feminine referents. For example, the word "salesperson" covers both masculine ('salesman') and feminine ('saleswoman') forms.
Using plural forms is often common gender/gender neutral as well, while retaining stylistic prescriptions. e.g. "a teacher often finds that he/she has high TTT" -> "teachers often find that they have high TTT".