Standard field visualization weblets are shipped with LANSA. They provide a standard visualization for many of the common field types and they are used by the XSL generator (when you compile your WAM) if a specific field visualization is not specified for a field in a web_map. For example, if you specify a field of type DATE in your web_map, the XSL generator will use the std_date field visualization by default when it generates the XSL for your webroutine.
A full description of the standard field visualization weblets, their properties and how to use them in your own webroutines is provided.
You should not modify the shipped weblets. Every time a Partition Initialization is executed, these weblets are re-imported and the original weblets in the repository are overwritten. If you wish to customize a field visualization weblet, save it first with a different name in the LANSA Editor and then modify the weblet copy. Don't start your own weblet names with 'std_' as they may conflict with weblets shipped by LANSA.