We actually have separate lists for different types of files (text, data, images, fax, audio, video, executable, etc). The API checks against each category to see if a file extensions is allowed. An extension can exist in more than category i.e. png is in fax and image). Internally we use these lists to enforce certain things like you can’t fax an exe. The list I posted was just a dump of the extensions without the category. Sorry about the dupes.
This is the base list that is used in every app. Our production operations team has the ability to manipulate the list per app I believe, but that is rare.
Do Infusionsoft also consider other file formats? like .STEP and .dxf? What if people from MFG/Construction users want to upload those 3D files per contacts?