What exactly is "equaling" a listing- does that just mean the claimant's specific condition is not listed under the body system but meets severity criteria?

If the claimant does not have an impairment that is not described in the Listings, First, SSA will find the Listing (or Listings) that is closely analogous to the claimant’s impairment. SSA will then take the medical findings related to the claimant’s impairment and compare them to those in the closely analogous listed impairment. The claimant will equal the Listing if the medical findings related to his impairment are at least of equal medical significance to those in the closely analogous listed impairment.

Under Social Security regulations, an impairment will be found medically equivalent to a Listed impairment “if the medical findings are at least equal in severity and duration to the Listed impairments.” This is done by comparing the claimant’s symptoms, signs, and lab findings with those specific for the Listed impairment; or if the condition is not Listed, with that Listing most similar to the claimant’s impairment.