Making splitter bar settings
Splitter bar settings are made at the form level, using the Form property sheet in Design Mode. These become the default settings for that form.
Note: Only users with Full User, Site Developer, or Vendor Developer
editing permissions can make default settings for splitter bars, and then only
for their authorized editing scope.
To make default splitter bar settings for a form:
You must exit Design Mode and then close and reopen the form to see your changes.