w:vertAlign (Vertical Alignment)

Description

w:vertAlign positions the run text as superscript or subscript relative to the surrounding baseline. It is defined in ECMA-376 Part 1 §17.3.2.42.

The offset and size reduction applied to the glyphs are determined by the font and renderer; the element itself only specifies the intent. For precise control, combine with w:sz (to set absolute size) and character position adjustment via w:position.

Attributes

Examples

<!-- E=mc<superscript>2</superscript> -->
<w:r><w:t>E=mc</w:t></w:r>
<w:r>
  <w:rPr>
    <w:vertAlign w:val="superscript"/>
    <w:sz w:val="20"/>
  </w:rPr>
  <w:t>2</w:t>
</w:r>

new Run(new Text("E=mc")),
new Run(
  new RunProperties(
    new VerticalTextAlignment { Val = VerticalPositionValues.Superscript },
    new FontSize { Val = "20" })  // Small size for superscript
  ,
  new Text("2"));

<!-- H<subscript>2</subscript>O -->
<w:r><w:t>H</w:t></w:r>
<w:r>
  <w:rPr>
    <w:vertAlign w:val="subscript"/>
  </w:rPr>
  <w:t>2</w:t>
</w:r>
<w:r><w:t>O</w:t></w:r>

new Run(new Text("H")),
new Run(
  new RunProperties(new VerticalTextAlignment { Val = VerticalPositionValues.Subscript }),
  new Text("2")),
new Run(new Text("O"));

Notes

• Baseline: w:val="baseline" (default) applies no vertical offset.
• Superscript: Raised above baseline; typically 33-50% smaller than normal text.
• Subscript: Lowered below baseline; typically 33-50% smaller than normal text.
• Font Size: w:vertAlign doesn’t change w:sz; combine with w:sz for explicit size control.
• Renderer Dependent: Exact offset and size reduction depends on font and rendering engine.
• Character Positioning: Use w:position (in half-points) for additional fine-tuning.
• Toggle Cancellation: w:val="baseline" cancels superscript/subscript from parent style.
• Common Use Cases: Mathematical equations, chemical formulas, footnote/endnote references.
• RTL Support: Works consistently with right-to-left and complex script text.
• Compatibility: All Office versions support superscript and subscript consistently.