They added documentation for MNFILTER and improved the documentation on other built ins. https://docs.oracle.com/en/cloud/saas/netsuite/ns-online-help/article_161950565221.html

Nice info. I wonder why they still don't have any documentation about

BUILTIN_RESULT

that was mentioned in the 2021.1 release notes.

SELECT BUILTIN_RESULT.TYPE_INTEGER("ROLE"."ID") AS "ID" /*{id#RAW}*/,FROM"ROLE"WHERE BUILTIN.MNFILTER("ROLE".accessprofiles, 'MN_INCLUDE', '', 'TRUE', '-2') = 'T'

Interestingly enough they use it in their MNFILTER example. It’s used in all of their analytics as well. They even mention that their doc will contain a full list

New built-in functions are available for you to use in SuiteQL queries. These new functions use the
BUILTIN_RESULT prefix and let you specify the result type of a SuiteQL expression. For example, you can
use the BUILTIN_RESULT.TYPE_DATE() function to specify that the expression result is a date.
For a full list of built-in functions, see the help topic Using SuiteQL with the N/query Module in SuiteScript