Bracketry are an intermediary component that attaches to a Mounting Structure, but also allows Equipment to be attached to itself. This can be the type of mounting bracket necessary to install a piece of equipment, or it can be a stand-off bracket that provides an extra attachment on a tower, or it might be a headframe which mounts to the top of a mast and provides multiple additional attachments. Bracketry does not attach directly to the ground or roof.
This category also includes Attachments, which are similar to brackets but often don't provide an explicit way for equipment to be attached to itself. Attachments often include ancillaries such as mesh screens, anti-climb attachments, bird spikes, etc.