A separate control character was not needed to indicate where your Hollerith string ended: it ended at the end of the Hollerith string. If you wanted to render a Hollerith string onto print media, you'd often want to feed the line and then return the carriage before printing the next Hollerith string. Of course, that wasn't strictly necessary if you were using a line printer, which would just print the line and advance.

The filesystems I used had 5 kinds of file: random-access, sequential, ISAM, Fortran-carriage-control and carriage-return-carriage-control. The only people who used the latter were the eggheads that used that new-fangled C programming language brought over from Bell Lab's experimental Unix system.

You're probably just looking for the record separator (036). If you are storing multiple text records and a block of memory, that would be the ideal ASCII code to separate them.