Using html in image captions

From Doc

You can put basic html in the captions for your images or video. Below is the basic html you would need to wrap around your captions to bold, underline, center, italicize, and/or adjust the font size of them.

To make a caption bold:
<b>This is a sample caption</b>

To underline a caption:
<u>This is a sample caption</u>

To increase the font size on a caption:
<font size="4">This is a sample caption</font>

Note, you can go as high as 5 for the font size. 

To center a caption:
<center>This is a sample caption</center>

To italicize a caption:
<i>This is a sample caption</i>

If you want to bold and adjust the font size, for example,
you can combine tags: 
<b><font size="5">This is a sample caption</font></b>