They could be made visible. On MSDOS it was common to have editors show an arrow as ESC or EOF, respectively pointing left or right. A lone CR was a musical note.

I am not sure whether RS could have replaced LF or CR+LF in this kind of free-format database; overloading record and line separators makes sense. But if FS-separated fields were a thing, people on MSDOS would have been used to seeing ⌙ as a field separator and likewise for other OSes.