[dgatwood]

The nice thing about SVG is that most recent readers let you search for text inside an SVG image (unlike, for example, text in a bitmap image). So it is almost as nice as incorporating it into the outer HTML; the only cost is a little extra markup complexity, plus the need to include two copies of the image markup and caption text/markup if you're producing content for Kindle because KF7 readers can't grok SVG. (This is where writing a few lines of actual software code can be helpful.)