If this value is not null, the string contained will be used to Page Forward (Page DOWN) within the screens presenting a multi-row FieldMap.
If the value is null, the PageForwardKey for the active TaskProject or UIProject will be used from the generic list class.
Examples:
M[enter]
Will send the "M" key (for "More") along with an Enter...for a host that doesn't use PageDown or F8 keys to scroll backward, but instead uses a "function" entry field
[pf10]
Perhaps the normal key is a PF8 and that is setup for the project, but for some reason this list screen was programmed to use a PF10 to page forward through the list...