<metamark> contains or describes any kind of graphic or written signal within a document the function of which is to determine how it should be read rather than forming part of the actual content of the document. [11.3.4.2 Metamarks]
<surface> <metamark function="used" rend="line" target="#X2"/> <zone xml:id="zone-X2"> <line>I am that halfgrown <add>angry</add> boy, fallen asleep</line> <line>The tears of foolish passion yet undried</line> <line>upon my cheeks.</line> <!-- ... --> <line>I pass through <add>the</add> travels and <del>fortunes</del> of <retrace>thirty</retrace> </line> <line>years and become old,</line> <line>Each in its due order comes and goes,</line> <line>And thus a message for me comes.</line> <line>The</line> </zone> <metamark function="used" target="#zone-X2">Entered - Yes</metamark> </surface>