Huffman coding generally works on symbols, where a symbol can be represented by any (possibly variable-length!) string of bits. I recall reading about a compression scheme (lzw?) where the symbol table had an entry for each raw byte value, plus the encoding instructions (e.g. lookback x bytes for y bytes).
That's pretty much all of them except LZW (which is an LZ78-alike, rather than LZ77). gzip has a number of Huffman tables for literals, distance, and for building Huffman tables at runtime... Yes, the instructions for building the Huffman tables used for decompression are themselves compressed using... more Huffman tables (HCLEN)!
Oh yeah, might have been remembering gzip. All I remember is that it was one of the old/common ones. Don't know why my mind jumped to lzw instead of the obvious gzip haha.