documentation for mysql_type and/or pgsql_type,

The handbook page on data types
http://drupal.org/node/159605

It seems (to me) to indicate that you can only use pre-ordained types in Drupal 6

- this would prevent things like:
* Boolean type
* enum type
* spatial data types

There is a discussion specifically about location data here:
http://groups.drupal.org/node/7558#comment-26055

Which suggests it may be possible to add new data types - is this possible for D6?

It would be great if the handbook could be updated to show how this can be done :-)

If these types can't be used with the Schema API - is there any recommendation on how best to proceed?

Presumable one could just use db_query() to create and maintain such tables ...

Again - some documentation would be useful.

Thanks - and let me know if I can help.