It would allow the user to "tag" records in a browse window for certain operations.
These tags would be at the developers discretion, and when used in conjunction with a function key (i.e. F8) processing would occur only on the tagged records.
The tagging would need to be retained until the user exited the file.
This way the user could scroll down in browse mode and tag records from screen to screen.
There are many applications that would benefit from this.