I had the same questions (plus some others) after trying to encode a sample finding aid. 1. With regard to the "level" attribute for <c>, I only set the attribute at the series and sub-series level. Below that, our entries can be any of a number of levels, depending on how much we used a hierarchical formatting to generalize over a range of folders and to eliminate repetition. We would do: Meetings Washington, D.C. San Diego Philadelphia Rather than: Meetings: Washington, D.C. Meetings: San Diego Meetings: Philadelphia When this starts going down a few more levels, these general headings (not really sub-series and not really files) can be impossible to tag consistently and without using multiple levels of subs (sub-sub-sub-sub-series). I opted to 1) use the numbered components <c01>, <c02>, etc., and 2) did not set the attribute beyond a "real" sub-series. 2. I had the same question about whether the <unitdate> is part of or separate from the <unittitle> and opted for the former, based in part on the fact that the dates are considered part of the title field 245 in the MARC-AMC format. My reading is the same as Alvin's - either is legal as the DTD is written, so it's a matter of convention. Rich Szary