data.MEASUREMENTREL

data.MEASUREMENTREL Measurement expressed in real-world (e.g., centimeters, millimeters, inches, points, picas, or pixels) or virtual units (vu). 'vu' is the default value. Unlike data.MEASUREMENTABS, in which only positive values are allowed, both positive and negative values are permitted.
Module MEI
Used by
att.distances (@dynam.dist), att.lyricstyle (@lyric.align), att.spacing (@spacing.staff), att.staffDef.vis (@spacing), att.visualoffset.ho (@ho), att.visualoffset.vo (@vo), att.visualoffset2.ho (@startho), att.visualoffset2.vo (@startvo)
Declaration
<content>
<rng:data type= "token">
<rng:param name= "pattern">
(\+|-)?\d+(\.\d+)?(cm|mm|in|pt|pc|px|vu)?
</rng:param>
</rng:data>
</content>

MEI Guidelines Version 3.0.0