aestheticsymbols
Use in a combo

Right ceiling copy & paste

⌉ is right ceiling, a plain-text Unicode symbol from the Miscellaneous Technical block. On Aesthetic Symbols it lives in the borders & shapes collection. As plain text it takes on the font and colour of wherever you paste it — a bio, a username, a caption or a stream title.

Unicode
U+2309
HTML entity
⌉
CSS content
\2309
JavaScript
\u{2309}
UTF-8 bytes
E2 8C 89
Made of

U+2309 ⌉ · Miscellaneous Technical

Will it show up? · Long-established text symbols

Plain-text characters from blocks that mainstream desktop and mobile fonts have covered for years. These are the safe ones.

Worked out from how each character is encoded, not from a test on a real device.