comparison is <a href=#case-sensitive id=case-sensitivity:case-sensitive-2>case-sensitive</a>.</p>
<p>Everything else (attribute values on <a href=#html-elements id=case-sensitivity:html-elements-3>HTML elements</a>, IDs and classes in
<a href=#no-quirks-mode id=case-sensitivity:no-quirks-mode>no-quirks mode</a> and <a href=#limited-quirks-mode id=case-sensitivity:limited-quirks-mode>limited-quirks mode</a>, and element names, attribute
names, and attribute values in <a href=#xml-documents id=case-sensitivity:xml-documents>XML documents</a>) must be treated as
<a href=#case-sensitive id=case-sensitivity:case-sensitive-3>case-sensitive</a> for the purposes of selector matching.</p>
<p>Everything else must be treated as entirely <a href=#case-sensitive id=case-sensitivity:case-sensitive-3>case-sensitive</a> for the purposes of
selector matching. This includes:</p>
<ul class=brief><li> IDs and classes in <a href=#no-quirks-mode id=case-sensitivity:no-quirks-mode>no-quirks mode</a> and <a href=#limited-quirks-mode id=case-sensitivity:limited-quirks-mode>limited-quirks mode</a>
<li> the names of elements not in the <a href=#html-namespace-2 id=case-sensitivity:html-namespace-2>HTML namespace</a>
<li> the names of <a href=#html-elements id=case-sensitivity:html-elements-3>HTML elements</a> in <a href=#xml-documents id=case-sensitivity:xml-documents>XML documents</a>
<li> the names of attributes of elements not in the <a href=#html-namespace-2 id=case-sensitivity:html-namespace-2-2>HTML namespace</a>
<li> the names of attributes of <a href=#html-elements id=case-sensitivity:html-elements-4>HTML elements</a> in <a href=#xml-documents id=case-sensitivity:xml-documents-2>XML documents</a>
<li> the names of attributes that themselves have namespaces
comparison is <a href=#case-sensitive id=case-sensitivity:case-sensitive-2>case-sensitive</a>.</p>
<p>Everything else (attribute values on <a href=#html-elements id=case-sensitivity:html-elements-3>HTML elements</a>, IDs and classes in
<a href=#no-quirks-mode id=case-sensitivity:no-quirks-mode>no-quirks mode</a> and <a href=#limited-quirks-mode id=case-sensitivity:limited-quirks-mode>limited-quirks mode</a>, and element names, attribute
names, and attribute values in <a href=#xml-documents id=case-sensitivity:xml-documents>XML documents</a>) must be treated as
<a href=#case-sensitive id=case-sensitivity:case-sensitive-3>case-sensitive</a> for the purposes of selector matching.</p>
<p>Everything else must be treated as entirely <a href=#case-sensitive id=case-sensitivity:case-sensitive-3>case-sensitive</a> for the purposes of
selector matching. This includes:</p>
<ul class=brief><li> IDs and classes in <a href=#no-quirks-mode id=case-sensitivity:no-quirks-mode>no-quirks mode</a> and <a href=#limited-quirks-mode id=case-sensitivity:limited-quirks-mode>limited-quirks mode</a>
<li> the names of elements not in the <a href=#html-namespace-2 id=case-sensitivity:html-namespace-2>HTML namespace</a>
<li> the names of <a href=#html-elements id=case-sensitivity:html-elements-3>HTML elements</a> in <a href=#xml-documents id=case-sensitivity:xml-documents>XML documents</a>
<li> the names of attributes of elements not in the <a href=#html-namespace-2 id=case-sensitivity:html-namespace-2-2>HTML namespace</a>
<li> the names of attributes of <a href=#html-elements id=case-sensitivity:html-elements-4>HTML elements</a> in <a href=#xml-documents id=case-sensitivity:xml-documents-2>XML documents</a>
<li> the names of attributes that themselves have namespaces