The escaping section currently says:

2.1.10.3 Escaping
Repositories MUST support the escaping of characters using a backslash () in the query statement. The backslash character () will be used to escape characters within quoted strings in the query as follows:
1. \' will represent a single-quote(') character
2. \ \ will represent a backslash () character
3. Within a LIKE string, % and _ will represent the literal characters % and _, respectively.
4. All other instances of a \ are errors.

From the above, it's not clear which BNF symbols this applies to.

For example, does this apply only to <character string literal>?
Does it also apply to <text search expression> (since it happens to have quotes around it) and/or <phrase>? Phrase is handled separately in the CONTAINS chapter.
Additionally, does this apply to <folder id>, which is itself a <character string literal>, or does "within quoted strings" apply only to quoted literal strings?