In HTML, <dfn> is used to mark a word that will be defined.

I personally prefer to use them in a slightly different way, I prefer to use it whenever I have a
"words as words" use:

    https://en.wikipedia.org/wiki/Use–mention_distinction
    https://en.wikipedia.org/wiki/MOS:WORDSASWORDS

To style these:




/* --==##  give a background color to <dfn>s  ##==-- */
dfn {background-color: #cfc}                /* light green */
a dfn {background-color: #afe}              /* light teal */
a:visited dfn {background-color: #ded}      /* nearly a light gray, since green + purple is brown or gray*/
a:hover dfn {background-color: inherit}