A transposition takes place when the author indicates that the order of two scraps of text have to switch places. In this case, each 'scrap' will need a @type="transposition" attribute, and a unique @xml:id.
For example:
[xml]
<seg type="transposition" xml:id="trans1">It is</seg>
<seg type="transposition" xml:id="trans2">perhaps</seg> something breaking,[/xml]
Don't be alarmed if the transposition is not immediately visualized: this visualization will only occur when we have declared the @xml:ids for transposition in the header.
For example:
[xml]
<listTranspose>
<transpose>
<ptr target="#trans2"/>
<ptr target="#trans1"/>
</transpose>
</listTranspose>[/xml]