Acceptable Escape Sequences?

[gs]

Hi,
Rule 4.1 states

Only those escape sequences that are defined in the ISO C standard shall be used.

The explanatory text then refers the Reader to section 5.2.2 of the C99 Standard for a list of escape sequences. However, 6.4.4.4 also defines an escape-sequence syntax as

Code:

escape-sequence:
       simple-escape-sequence
       octal-escape-sequence
       hexadecimal-escape-sequence
       universal-character-name

and a hexadecimal-escape-sequence as

Code:

hexadecimal-escape-sequence:
       \x hexadecimal-digit
       hexadecimal-escape-sequence hexadecimal-digit

The use of '\x' i not mentioned in 5.2.2 as a valid escape-sequence. Are hexadecimal escape-sequences permitted under MISRA 2004 Rule 4.1?