BNF Grammar Quote issues

CMIS defers to SQL-92 for the description of <character string literal>. SQL-92 (http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt) defines a character string literal as delimited by <quote>, which is defined as <quote> ::= ', that is, a single-quote character.

CMIS BNF defines <quote> ::= '"' | "'", that is either a single- or double-quote character.

• Is CMIS attempting to "override" or "extend" the SQL definition of the <quote> production, or is CMIS's usage unique to where it is explicitly used in the CMIS text.
• Specifically, does CMIS's <quote> affect the <character string literal> as defined in SQL-92?

The <text search expression> for the CONTAINS operator is specified to be delimited only by double-quote characters, not the single-quotes prescribed for SQL-92 strings, nor the "either-quotes" used within the expression itself. The <datetime literal> is delimited with "either-quotes", unlike character string literals. The example in section 2.10.2.4.2.3 uses double-quotes, which hints that maybe CMIS is trying to override SQL's definition of <quote>.