As you create aliases for window-level Help topics, RoboHELP writes information about them to an alias file (.ALI). This file shows the relationship between the topic ID and the window-level Help topic (.HTM file).
The .ALI file is included in the HTML Help file (.CHM) when it's compiled.
When users request help, the HTML Help engine looks up the map number in the map file and translates it into its matching topic ID.
It looks up the topic ID in the alias file and translates it into its matching topic file name so the topic can be displayed in the application.
RoboHELP creates one alias file for each HTML Help project that you create. It uses the same name as the compiled .CHM file (for example, PizzaShack.CHM and PizzaShack.ALI).