Refer to this undated BLM document, an attachment to IM2009-018, Process for Setting Priorities for Issuing Grazing Permits and Leases.
Improve (I) – Not achieving rangeland health standards
Maintain (M) – Achieving rangeland health standards
Custodial (C) – Public lands produce less than 10% of forage
Category I allotments have the highest priority for processing authorizations, managing uses and monitoring rangeland health, according to IM2009-018.
These categories appear in some of reports from RAS.
RELATED: Rangeland Conditions in Horse-Free Areas.
Western Horse Watchers Association 
Can the information on your site and the changing pics be shared on social media, like Twitter? I would like to Tweet this, as I totally agree with your information & the changing pics depicting the gov’t & so-called WH protection orgs that are all out to eradicate our WH&Bs from our public lands.