DOC: Examples of monotonic/non-monotonic label-based indexing
Just ran into this gotcha and almost filed it as a bug report. Added a few examples to fill in the section header.

@nileracecrew Thanks for this nice contribution to the docs! (that title was indeed missing an explanation ;-))

It is certainly good to keep it here, but we maybe should also consider to include a similar explanation in the indexing docs itself.
 You're welcoem @jorisvandenbossche. Seems like this behavior is most likely to show up when you have other problems (in my case corrupted data, as well as an in another issue I found), but it is surprising. 

I made the suggested edits and re-committed.
 instead a empty frame use a range for number (range(6))
 Sorry, I don't quite understand your meaning. Do you mean fill the example DataFrame with numbers, or use range(6) as an index instead of the empty DataFrame example, or something else?
 fill with numbers
 @nileracecrew : If I'm not mistaken (unless the tests do check these files), since your fixes are purely documentation related, you should put <b>[ci skip]</b> in your commit message because you aren't changing any code.  Every time you make a change to your PR, you are adding another build to Travis (you currently have five).  Unless these `.rst` files are checked, I would suggest if someone could cancel all of your builds and you could put that "ci skip" tag in your commit.
 pls squash when you update
 Is there a quick way to render a single .rst file to see the output? GitHub doesn't render the ipython blocks.
 http://pandas-docs.github.io/pandas-docs-travis/contributing.html#how-to-build-the-pandas-documentation
 sorry, didn't mean to push that here
 thanks!
