man mktemp -p DIR use DIR as a prefix; implies -t [deprecated] -t interpret TEMPLATE as a single file name component, relative to a directory: $TMPDIR, if set; else the directory specified via -p; else /tmp [deprecated]
It is not clear what is deprecated, -p, or both. Move [deprecated] closer to the front of the sentence. Or add a DEPRECATED OPTIONS section. Also I know the info page says why, but at -u, --dry-run do not create anything; merely print a name (unsafe) the reader thinks 'why, will it grind up my filesystem?' If --dry-run is unsafe, then I'd hate to try --wet-run. Say (unsafe to use for ....).