...
All occurrences in a source file of the following sequences of three characters (that is, trigraph sequences) are replaced with the corresponding single character.
??=
#
??)
]
??!
|
<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="8ddaf7369c5f5118-4da31e24-480c4b94-903986fd-c00104f71fbe2b5f7e64a66f"><ac:plain-text-body><![CDATA[
??(
[
??'
^
??>
}
]]></ac:plain-text-body></ac:structured-macro>
??/
\
??<
{
??-
~
...
PRE06-A. Enclose header file in an inclusion sandwich 01. Preprocessor (PRE) PRE08-A. Guarantee that header file names filenames are unique