- inaccuracies (e.g. word separator in CL depends on current readtable), which is understandable given the very terse format

- missing cases (e.g. no compiler for CL?)

- and factually wrong elements (identifiers are case sensitive, but upcased while reading by default; they can starting with numbers, like 1+, etc.).

Fortunately there is a way to fix that: https://github.com/clarkgrubb/hyperpolyglot/issues