[this] as a synonym for [this][]

[Brian.Doherty at med.va.gov]

I've done a lot of reading over the years, technical and non-technical
works.  In my experience, square brackets are pretty rare outside of code
blocks.  People use parentheses in ordinary writing.  I'd guess that the
likelihood of an author using _two_ bracket pairs in a row in a prose
context is vanishingly small.  

The only place this might happen is in scientific articles with brackets for
bibliographic citations.  Even here, you can do what seems natural for a
text version of the article, and  Markdown ignores the citations.  Even if
you try to fake out Markdown by making your citation style similar to the
link syntax, it still works as expected.  If you're really bent on mixing
something like this with Markdown reference-style links, you could always
craft your link names to avoid confusing your readers who see the text
version.   You do have to keep a space between a [citation] (and a
parenthetical remark that immediately follows) to avoid making an
inline-style link, but that seems like the right thing to do anyway.  See
example below.  

My take:  why change anything?   


Example 
---

Our test showed results similar to those of [Smith][4].  Several other
groups were able to support these findings [5][6].  A table comparing these
tests is available online at [clinicaltrials.gov][link-1].  Another group
[Blake] (data not available for the table) supported the competing theory of
Davis [8]. 

[4]: Smith, Science 1999.  
[5] Jones, Nature 2000.  
[6] Doe, JBJS 2001.  
[Blake] Blake et al., Nature 2002.  
[8] Davis, Science 2000. 

[link-1]: http://clinicaltrials.gov	"Clinical trials registry"