What Metaschema fields are involved in CRC calculations?

What Metaschema fields are involved in table and database CRC calculations?
What parts of the schema definition affect table and index CRC values ?

CRC values are used to check if the database schema matches the expected schema for precompiled r-code.  Progress table and database CRC calculations involve the following fields from the _File, _Field, _Index and _Index-Field Metaschema tables:

 1.  _File:

•    _File-Name
•    _DB-lang

2.  _Field

•    _Field-Name
•    _Data-Type
•    _dtype
•    _sys-field
•    _field-rpos
•    _Decimals
•    _Order
•    _Extent
•    _Fld-stdtype
•    _Fld-stlen
•    _Fld-stoff
•    _Fld-case

3.  _Index

•    _Index-Name
•    _Unique
•    _num-comp

4.  _Index-Field

•    _Field-Name
•    _Ascending
•    _Abbreviate
•    _Unsorted

Prior to Progress 9.x:

Indexes of a table do not have their own CRCs, a change to an index is considered a change to the table.

• Any change to an index automatically changes the CRC value of a table.
• The resulting CRC is stored in the _CRC field of the _File record for the table.
• A CRC mismatch on a table or index referenced in the r-code would stop the r-code from loading.

Progress 9.x and later:

Indexes have their own CRCs.  Indexes can be added/dropped/modified without modifying the table CRC

• A change to the listed fields in _File or _Field automatically changes the CRC value of a table. The resulting CRC is stored in the _CRC field of the _File record for the table.
• A change to the listed fields in _Index or _Index-Field automatically changes the CRC value of the index. The resulting CRC is stored in the _Idx-CRC field of the _Index record for the index. Only applications that use a changed index must be recompile.
• In current releases (OpenEdge 11.x), due to changes to better support online schema changes and to have more portable code in DataServer environments, a mismatch CRC may not prevent the r-code from running under some instances. Namely, if the change to the table is a simple addition of one or more fields, the old r-code will still execute, even though the CRCs do not match.
• When the CRCs do not match, the AVM will check if the fields of the table (specifically their names, data types, extent and logical field record positions or _Field-rpos) have changed since the r-code was compiled.  If they have not changed, the AVM will run the old r-code.

References to other documentation:

Progress Programming Handbook, "R-code Features and Functions"
Progress Version 9 Product Update Bulletin, "R-code Features and Functions"

OpenEdge Deployment: Managing ABL Applications, R-code Features and Functions, "Database CRC changes that do not prevent r-code execution"