# hlpidx > [HTML Version](hlpidx.htm) _hlpidx_ may used to specify a variety of primarily GUI-oriented auxiliary features such as [Tool tips](tooltipsinfld.htm.md), [Mouse Click Strings](mouseclickstringsinfld.htm.md), [Help Keys](helpkeysinfld.htm.md), [Context Menu Handling](context_menu_handling.htm.md), and [Placeholders](placeholders.htm.md). Note that since the typical length requirement for the _hlpidx_ string can vary widely, it is particularly convenient to map it as a dynamic string; see S and X variables in [Dynamically Sized Variables](dynamically-sized_variables.htm.md).