Acronym expansion refers to a feature in some content management systems that provides automatic expansion of the first letters of words within phrases during electronic searches conducted through Web-based search engines.
For example, any time a user types in an acronym or abbreviation, the content management system will spell out the phrase or present you with a listing of matching phrases for the user to select from. Acronym expansion is used in data queries and provides suggestions relative to whatever was entered into the search function box.
Techopedia explains Acronym Expansion
The acronym expansion enables those who search the Web to receive various electronically automated choices relative to the initial few words they typed in.
This is beneficial for those with poor spelling or typing skills. For instance, the acronym for digital rights management is DRM. If a user types "DRM" into a search engine such as Google, matching phrases for that acronym will be provided, allowing the user to select the correct one. Some Web sites use acronym expansion when they register their domain with major search engines by linking up their website acronym expansion so that it is a type of copycat of authentic websites.