y-size Y Size of the Glyph

The number of rows in the bit-mapped glyph that has been declared with a <glyph-data> element as part of a <private-char> element.
OPTIONAL on element: <glyph-data>
Value Meaning
Number The number of rows (for example, “25”) used to define the glyph in a <glyph-data> element.
Restriction @y-size is an optional attribute; there is no default.
Tagged Sample

Row count for Arrow glyph bitmap

<private-char name="NORTHWEST SOUTHEAST ARROW" description="Arrow,
  normal weight, single line, two-headed, Northwest to Southeast">
 <glyph-data id="NWSEArr" format="PBM" resolution="300"
   x-size="34" y-size="34">