I was replying to your query about the use of the word "residual", based on reading the "published" material (that you quoted from) available on-line and my own knowledge of archaeological excavation, interpretation and archaeological report preparation. My explanation of the term "residual" is one that would be recognised and used in any archaeological setting. There may be pits/alignments which are Mesolithic in date (rather than containing residual material) that are not as yet available in a "published" form and are therefore unknown to me. I can only assume from what you have said about Mike Griffiths comments earlier in the year that this is the case.