Spaces vs tabs (documentation is contradictory)

Hi there,

as Gérard Talbot pointed out in a different thread [1], the
documentation regarding spaces vs tabs is contradictory:

"
Use tabs rather than spaces for indentation
"
http://testthewebforward.org/docs/test-format-guidelines.html#style-rules

versus

"
For indentation, spaces are preferred over tabs.
"
http://testthewebforward.org/docs/review-checklist.html#in-depth-checklist

What's the right option?
Please, update the documentation to avoid misunderstandings.

Thanks,
  Rego

[1]
http://lists.w3.org/Archives/Public/public-css-testsuite/2014Nov/0008.html