The following from RTF spef 1.6 may be of use:
- \pgnhnsm Em-dash (—) separator character.
- \pgnhnsn En-dash (–) separator character.
- \emdash Em-dash (—).
- \endash En-dash (–).
- \- Optional hyphen.
- \_ Nonbreaking hyphen.
Perl is Huffman encoded by design.