Record Fields and the Component Buffer

This is taken directly from peoplebooks;
The record fields in the component buffer are a superset of those accessible to the user through page controls. In most cases, PeopleCode can reference any record field in a scroll area’s primary scroll record or in a related display record, not just those fields that are associated with page controls. The following table lists record types and locations:

Type and Location of Record	Presence in Component Buffer
Primary record on scroll levels greater than zero	On scroll levels greater than zero, all record fields from the primary scroll record are in the component buffer. PeopleCode can refer to any record field on the primary scroll record, even if it is not associated with a page control.
Primary record on scroll level zero	If scroll level zero of a page contains only controls associated with primary scroll record fields that are search keys or alternate search keys, then only the search key and alternate search key fieldsave in the component buffer, not the entire record. The values for the fields come from the keylist, and the record cannot run RowInit PeopleCode. If level zero contains at least one record field from the primary scroll record that is not a search key or alternate search key, then all the record fields from the primary scroll record are available in the buffer. (For this reason, you may sometimes need to add one such record field at level zero of the page to make sure that all the record fields of the level-zero primary record can be referenced from PeopleCode.)
Related display record fields	The buffer contains the related display record field, plus any record fields from the related display record that are referenced by PeopleCode programs. You can reference any record field in a related display record.
Derived/work record fields	Only derived/work record fields associated with page controls are in the component buffer. Other record fields from the derived/work record cannot be referenced from PeopleCode.
Translate table record fields	Only Translate table fields associated with page controls are available in the component buffer. Other fields from the Translate table cannot be referenced from PeopleCode.