These days, older aircraft are constantly being upgraded with modern avionics and technology, often with an STC. Best practice is to track these on the report to ensure airworthiness and have everything on one sheet / one report.
To do this, navigate to your aircraft profile and create an AD Compliance Report or if already in your AD Report Prep page itself, click on "Manually Add Appliance Info" (below Propeller Info):
For example, if a user wanted to add the JPI Electronics digital tachometer (STC #SA00061LA), you could fill in the following and then hit Save.
Returning back to building your AD Report (the AD Report Prep Page) - you can see the STC pop up in the appliance section with the applicable STC#:
