>>> Missing leading whitespace
word pas~~t~~ word
<<<
<p>word pas<del>t</del> word</p>
>>> Missing trailing whitespace
word ~~p~~ast word
<<<
<p>word <del>p</del>ast word</p>
>>> Middle of word
word p~~as~~t word
<<<
<p>word p<del>as</del>t word</p>
>>> Whitespace after opening
word~~ past~~ word
<<<
<p>word~~ past~~ word</p>
>>> Whitespace before closing
word ~~past ~~word
<<<
<p>word ~~past ~~word</p>
>>> mixed with emphasis and order changes
**~~first~~** ~~**second**~~
<<<
<p><strong><del>first</del></strong> <del><strong>second</strong></del></p>