Values and units

Hello,

I've received a good advice to model table of caracteristics with http://tdg.docbook.org/tdg/5.0/segmentedlist.html

In the body of a text, what is a good way to model a value with the associated unit ?

Example : I am <data><value>1,8</value> <unit>m</unit></data> high

Need is to avoid <data>1,8meter</data> or <unit>meter</unit>, <unit>M.</unit> to enable consistency (readability) or even conversion between units

Thank you for your feedback,

Florimond