Minor copy editing, resolving the easier points from my long mail:

p 1, title matter:
  Minimal version of my full address.

p 1, Sect I, col 1, bullet 1:
  Simpler formulation, and consistent plural.

p 2, col 1, paragraph 3 "Of course, NeXus strives ...":
  Deleted as overly redundant with what has been said in Sect I.

p 2, col 2, "provided by the NeXus class name":
  Indicated that this is realized as a HDF5 attribute.

p 3, Sect IIIA2, bullet 1:
  "The array's first dimension is the number of ..." Categorically
  impossible, a dimension (meant here in the sense of axis, not of
  rank) can contain a given number points, but it "is" not a number.
  Corrected into "The array's first dimension is the scan axis."

Same subsection, last sentence:
  Deleted spurious "is" from "is behaviour is".

p 4, Sect IV, paragraph 1, line 5:
  "possible" -> "allowed"

p 4, Sect IV, paragraph 1, lines 11:
  "names" -> "keywords to designate groups and fields"

p 4, Sect IV, paragraph 1, lines 12-13:
  "for all the names in a NeXus base class"
  -> "for all allowed keywords".

p 4, Sect V, paragraph 1, sentence 4:
  Deleted as fully redundant.

p 5, Sect VII:
  Changed to avoid calling some facilities "relevant", which sounds
  unfriendly towards the others.

p 5, Sect VIII:
  Deleted void statement "still exists and".

p 5, Sect IX, last sentence:
  Changed. No longer suggest one might hesitate to consult a WWW-site.

p 5, Ref 1:
  Reformatted like a regular journal reference.

14 times:
  "HDF-5" -> "HDF5", which seems to be the official form.