title: Is there a way to hide figure captions when using knitr and pandoc to create docx files?
body: <p>I am using knitr and pandoc to write reports into word (we need to be able to circulate for comments using track changes etc).</p>
  
  <p>It is working very well so far, but I have found that the plots are all coming out with captions at the bottom, and I don't want captions.  While I could just delete them in the word doc, if I can stop them showing in the code it would be better.</p>
  
  <p>So for the following code in markdown:</p>
  
  <pre><code>Test test test
  
  ```{r}
  summary(cars)
  ```
  
  You can also embed plots, for example:
  
  ```{r fig.width=7, fig.height=6}
  plot(cars)
  ```
  </code></pre>
  
  <p>I then run the following code in R:</p>
  
  <pre><code>library("knitr")
  
  # Stackoverflow table test 1.html
  
  knit2html("captiontest.rmd")
  
  FILE &lt;- "captiontest"
  
  system(paste0("pandoc -o ", FILE, ".docx ", FILE, ".md"))
  </code></pre>
  
  <p>And the graph, in the word document, has the caption "plot of chunk unnamed-chunk-2"</p>
  
  <p>I know I can change this caption, e.g. <code>{r fig.width=7, fig.height=6, fig.cap='hello'}</code>, but I thought that <code>fig.cap=NULL</code> would make it hidden.  Instead it seems to make the whole plot disappear.</p>
  
  <p>Are plots required to have a caption - do I just have to go through each word doc and delete them manually?  Or is there a way to hide them?</p>