this kind of broad situation is hard to fix; usually a particular thought has a particular solution. Similarly, using a synonym lookup may hold you back. Look at what you want to say, not what individual words you'd pick without any constraints.
A trick is to try to say how you know of such folks, finding a path or paths along which you can form a link, such as "my dad's mom's son" or "my pal's husband's pal" or "a woman who knows my boss from an old job" or "I know of a particular lady's writings from a class I had at school".
This social platform's author own account within said platform shows an additional gimmick or option, viz., translation, insofar as you'd normally hail said author as "[small gray animal with a tail]", but within this platform's constraints as "[said animal, only in Latin]".
This is not so hard for participants whom you call with words common to kinds of things, kinds of animals, jobs, and so on, but possibly difficult for folks lacking a commonality of naming of this sort (viz., with "nomina propria").
(Sorry if "viz." is illicit on account of what it actually stands for... you can just think of it as "in particular" if you want.)
But if you say "300" in words and not digits, you would say two words both lacking suitability for that forum. So I ask, possibly oratorically: by what logic is "300" OK if "viz." (or "BRB") isn't?
So 300 is okay: I do not recoil from a foul glyph in it.