Why my SQL Profile has not been picked up?

Somtimes you might be into a situation, that you have created an sql profile and unfortunately that has not been picked up?

Well as per my reads and understanding and limited knowledge, these may be the causes.

1) Signature mismatch - SQL statements as converted to signature (with possible extra space truncation, replace literals etc)

2) Force Matching = False, Assume you have created a sql profile for a statement that contains literal values of 10,20. where the current statement is using different literals, You have to keep force_matching option to true in order to accept or work with profile even though there is a mismatch. Force Matching is something like cursor_sharing=force (tanel poder)

3) Invalid hints - Due to version changes, (Kerry Osborne) , some change in mechanism, for example, INDEX_XXX (table_name.column_name) hint is the simple INDEX(alias index_name) hint.
Note: If a hint is invalid the whole sql profile wont be invalidated, the optimizer just simply ignore that part of hint and rest of execution path will be same , but different plan

4) Dynamic Queries (Tanel Poder), Yes the dynamic generated queries may give you different combinations and its impossible to have signature will be same.

5) Category, that placed at database level is different from the category in the sql profile

6) Underlying object changes, A sql profile having with a statemetn that contains a "view" representation, but the view got changed aftersome tiem due to the view's underlying column order changes, the SEL$ may change in the view and as well as the sql profile which will be invalid and sql profile silently ignored (Confusing part, but yes can happen, I will write up with examples on this)

7) Cardinality especially when non static tables like GTT, when you create a profile when the GTT has some data in it and you want to use the same profile when GTT does not has rows at all. This may cause to change the plans and profile is of no use then (Bryan)

If anyone knows about more than above, please comment and I will update in the list too

Thanks
Geek DBA