Insert:
Regular expressions are implementation dependent expressions that, at a minimum, conform to the requirements of Conformance Clause C1 of Unicode Technical Standard #18: Unicode Regular Expression Guidelines, Version 13, using Perl Regular Expressions syntax.

Inserted: Regular expressions are implementation dependent expressions that, at a minimum, conform to the requirements of Conformance Clause C1 of Unicode Technical Standard #18: Unicode Regular Expression Guidelines, Version 13.

At table:operator, and table:use-regular-expressions, but not table:search-criteria-must-apply-to-whole-cell.

Note that the language of table:search-criteria-must-apply-to-whole-cell uses the phrase "search criteria." I asked Eike about replacing that with regular expression and here is his reply (which is why I did not insert the regular expression language):

***
The attribute is not only for regular expressions as search patterns,
it applies also if table:use-regular-expressions='false' and the string
is a literal, or if table:use-wildcards='true', hence the wording
"search pattern". Replacing it with "regular expression" would be
misleading.
***