Doc: NR 4.1.2: Setting alist keys properly. (issue2670041)

[markpolesky]

Reviewers: ,

Message:
I was about to push this, but then I started thinking that
the change was big enough to ask you guys for approval.
Any opposition?  I'm aiming for clarity, accuracy, and
comprehensiveness.  The idea is to reduce the amount of
time users spend being confused, and reduce the number of
questions on the mailing list.

Comments?  Okay to push?

Thanks.
- Mark

Description:
Doc: NR 4.1.2: Setting alist keys properly.

Please review this at http://codereview.appspot.com/2670041/

Affected files:
  M Documentation/notation/spacing.itely