"RFC" stands for residual functional capacity. It is an important term to understand that the SSA uses in the analysis towards whether or not a person is disabled under their definition. Essentially, they are trying to define what the limitations are and resulting type of work they can perform (e.g. sedentary, light, etc). It is not absolutely scientific but an attempt to be specific about limitations (either mental or physical). Examples of physical limitations may relate to how long a person can stand/sit continuously, how much they can lift and how frequently, etc. Click on this link for an RFC form to help document a claimant's physical limitations.