Comprehension

For the duration, you understand the literal meaning of any language that you hear or read. You can also read 100 words a second (6000 words a minute) and until the spell ends, you additionally are magically imbued with the keen mind feat. When the spell ends roll a 1d20 to determine how much you retain.

1-5 You only remember bits and pieces of what you learned

6-10 You can recall only the major points of what you learned

11-17 You retain most of what you learned only losing minor details

18-20 You retain everything which you learned

This spell doesn't decode secret messages in a text or a glyph, such as an arcane sigil, that isn't part of a written language.