Caveat lector is a Latin phrase meaning "Let the reader beware."
The phrase is used in written English in two distinct ways:
it warns the reader that a passage may be erroneous in its details, but not in the general idea. The writer is at pains here to ensure the reader knows the possibility of mistakes in the work
it warns the reader that a passage may be problematic in the general idea, e.g. misleading, rather than in the written details themselves
Examples
(first meaning) "XYZ store, at 1600 Main Street, said in the newspaper they are selling scooters for only $9.99. Caveat lector?the print was smudged and I may have got the address details wrong."
(second meaning) "XYZ store said in the newspaper they're selling scooters for only $9.99. Caveat lector?they don't mention that you have to pay extra for the wheels."