confusing ReST/html

[Randy Dunlap <rdunlap@infradead.org>]

I'm comparing Documentation/core-api/index.{rst,html} and
Documentation/driver-api/index.{rst,html}.

Lots (but not all) .rst files end with something like

.. only:: subproject and html

   Indices
   =======

   * :ref:`genindex`

Both of the core-api & driver-api index.rst files do...
with the difference being that core-api/index.rst has
one space following ".. only::" while driver-api/index.rst
has 2 spaces following ".. only::".

Does that make a difference?

When looking at the end/bottom of core-api/index.html,
there is *NO* heading "Indices" and *NO* link "Index" as there
is in driver-api/index.html.
Why? 

There are other cases like this one:

$ cd Documentation; git grep "^\.\. only:: [^ ]"

RCU/index.rst:.. only:: subproject and html
core-api/index.rst:.. only:: subproject and html
rust/index.rst:.. only:: rustdoc and html
rust/index.rst:.. only:: not rustdoc and html
trace/index.rst:.. only:: subproject and html
virt/index.rst:.. only:: html and subproject
wmi/devices/index.rst:.. only:: subproject and html


thanks.
-- 
~Randy