Incorrect. The whole sentence is:

"may be aborted if a file contains content that appears to be binary, Unicode text, or text with CR/LF line endings unless the interactive user chooses to proceed. If there is no interactive user or these warnings should be skipped for some other reason, the --no-warnings option may be used."

I use fossil and checking in binaries works beautifully. You _do_ get a warning, but as seen in the documentation, you can use --no-warnings if you don't want that.

Note however, that you can't use diff on binaries, and since the entire history of the repository and the versions is shipped to all developers, storing large binaries quickly becomes cumbersome. I would in that case, store links to binaries, which themselves are stored in an archive, or switch to another scm program.