As an example of having not-exactly-a-character as Unicode "characters", it is rather rare that musical symbols are embedded in running texts (which is a primary litmus test for encoding), but musical symbols are typically rendered with existing font technology so there are needs for standardized "character" codes, as SMuFL [1] does. In fact Unicode 18 will get tons of musical symbols that have been in SMuFL for a long time but not yet in Unicode [2].

[1] https://www.smufl.org/

[2] https://www.unicode.org/L2/L2025/25017-miscellaneous-musical...