Disadvantage is part of advantage/disadvantage mechanic of 5e and both seems similar, although different enough.
Advantage/disadvantage is a single mechanic, so I think it should have one master tag. When advantage was made our tag name character limit was too small for advantage-and-disadvantage (26, 1 too many).
Now that we have more characters to use, we should just rename it advantage-and-disadvantage. That would be findable by typing
disad..., so we might not need a disadvantage tag, but because the new tag would be long, it would probably help to have it as a synonym for those who don't notice “…-and-disadvantage” trailing off the end. That way we'd have:
(Also, if we find that we need to use either of the shorter ones for another game that has completely different things called “advantages” and “disadvantages”, like GURPS does for its chargen pieces, we have the option of breaking the synonyms at that later date.)
@SevenSidedDie raises a very good point, but here is a shorter alternative to the long tag he suggested:
This style is frequently used by writers and is prolific in legal documents referencing multiple genders as
(s)he so that they don't need to write
he and/or she.
I am not sure how the Tag Search would handle searching
disad but it should appear for both
dis as well as