[lex.header] (original) (raw)

The appearance of either of the characters ' or \ or of either of the character sequences or in aq-char-sequence or an h-char-sequenceis conditionally-supported with implementation-defined semantics, as is the appearance of the character" in an h-char-sequence.

[Note 2:

Thus, a sequence of characters that resembles an escape sequence can result in an error, be interpreted as the character corresponding to the escape sequence, or have a completely different meaning, depending on the implementation.

— _end note_]