How do I create a Dictionary Renderer for peaceful purposes?

[Anonymous User]

I have some electric utility featureclasses that have some fairly complex symbolization requirements.

I would like to leverage Dictionary renderer to symbolize them.

However when I go into Symbology and choose Dictionary all I see are military choices.

How do I create a new entry for this dropdown called Electric?

I looked here, but didn't see anything to indicate this can be used for anything except military purposes.

Update

I tried copying the mil2525d folder to Electric, and renaming the contained .stylx file to Electric.stylx.

However,  that had no effect on the dropdown list in the Symbology UI.

Thanks, Kirk