FAA has published a charting notice (PDF) that describes how equipment requirements will be noted on terminal procedure charts. This change is based on a long discussion at the Aeronautical Charting Forum (see 13-02-312: Equipment Requirement Notes on Instrument Approach Procedure).
For procedures with PBN elements, the PBN box will contain the procedure’s navigation specification(s); and, if required: specific sensors or infrastructure needed for the navigation solution; any additional or advanced functional requirements; the minimum Required Navigation Performance (RNP) value and any amplifying remarks. Items listed in this PBN box are REQUIRED. The separate Equipment Requirements Box will list ground-based equipment requirements. On procedures with both PBN elements and ground-based equipment requirements, the PBN requirements box will be listed first.
The publication of the new notes will continue incrementally until all charts have been amended to comply with the new standard.
A sample of the new notes boxes is below.
Here’s an example of the requirements box on the recently updated chart for the ILS RWY 28R approach at Billings, MT (KBIL):