2 statements about plan stability/stored outlines are true?

1.You can group outlines in categories.
2.You can only have one stored outline per SQL statement.
3.Plan stability only wants when SQL statements match textually.
4.Stored outlines are saved in data dictionary SYS schema
5. Stored outlines become invalid when you analyze the associated objects.

I think 1 & 4

but suspicious about the location of stored outlines where they are stored in SYS schema or OUTLN schema