Outside of tag.
<h3>Sample HTML <abbr title="Pabst Blue Ribbon">PBR</abbr></h3>
<p>Simple substitution: Placeat <abbr title="Pabst Blue Ribbon">PBR</abbr> etsy scenester. Consectetur vinyl mixtape beard ea mcsweeney's butcher_brunch, nihil laboris viral. Yr <abbr title="Video Home System">VHS</abbr> gluten-free 8-bit. Ad magna butcher readymade banksy.</p>
<br />
Ignore abbreviations in tags -- substitute text only: Next level vero mustache, <a title="PBR" href="/pbr"><abbr title="Pabst Blue Ribbon">PBR</abbr></a> freegan cosby sweater tattooed salvia viral art party hoodie synth whatever. Vinyl messenger bag keffiyeh, <a title="This is PBR of course" href="/pbr"><abbr title="Pabst Blue Ribbon">PBR</abbr></a> dolore sed keytar brunch vice exercitation wolf. Fixie art party in eu laborum.
<br />
Abbreviation present in original: <abbr title="Pabst Blue Ribbon"><abbr title="Pabst Blue Ribbon">PBR</abbr></abbr>
<br />
<p>More difficult ones: Butcher pariatur gluten-free, adipisicing four loko esse PBR-YUM mixtape culpa-squid master cleanse/consequat. Accusamus qui 3 wolf moon officia. Nesciunt labore sed artisan. Messenger bag aliqua nostrud pitchfork, sed <a title="VHS" href="/vhs">My <abbr title="Video Home System">VHS</abbr>'s</a> ad iphone laborum magna american apparel fanny pack thundercats.</p>
Outside of end tags <abbr title="Pabst Blue Ribbon">PBR</abbr>.
A tricky abbreviation has <abbr title="This bar is over">TB-IO</abbr> hyphens in it.
What about a <abbr title="Transmission control protocol, internet protocol">TCP/IP</abbr> abbreviation which has slashes.