Does any SQL standard include a REF CURSOR or TABLE type definition?

I always find it hard to read the rather abstract SQL standard specification, for instance this document here:

http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt

I'm wondering, is any of the major RDBMS's supported concepts of REF CURSOR's (Oracle, Postgres, SQL Server, ...), or TABLE types (which can be used as nested tables, e.g. in Oracle), or any related concept standardised in some way?

For instance, HSQLDB, a very standards-compliant d开发者_如何学编程atabase (since version 2.0) supports the UNNEST function to unnest ARRAY types into tables. This concept of unnesting can be considered part of the non-first normal form in relational modelling, which seems to be a common concept. That's why I thought it might be worth standardising...