consists of → is

The existing sentence (which is analogous to the sentences directly above) sounds like an HTML tag is composed of these many things, while the example shows it can be either one of them.

Author: ePaul

spec.txt

@@ -9029,7 +9029,7 @@ A [CDATA section](@) consists of
 the string `<![CDATA[`, a string of characters not including the string
 `]]>`, and the string `]]>`.
 
-An [HTML tag](@) consists of an [open tag], a [closing tag],
+An [HTML tag](@) is an [open tag], a [closing tag],
 an [HTML comment], a [processing instruction], a [declaration],
 or a [CDATA section].