The term 100% recycled means that all of the pulp has been made from recycled paper, while x% recycled means that x% of recycled pulp has been mixed with chemical (virgin) pulp.
The term post-consumer means that the recovered paper comes from selected used papers, either domestic or industrial. However, the term pre-consumer indicates that the paper industries' own paper waste is remixed with pulp, perhaps virgin. Thus, pre-consumer paper is not truly considered to be recycled as such.