# `GSGlyph validateKerningGroup:error:`

*Instance Method*

Validates the syntax of a proposed kerning group name.

## Declaration

```swift
func validateKerningGroup(_ ioValue: AutoreleasingUnsafeMutablePointer<AnyObject?>?) throws
```

```objc
- (BOOL) validateKerningGroup:(id*) ioValue error:(NSError **) outError;
```

```python
validateKerningGroup_error_(ioValue: object) -> tuple[bool, NSError]
```

## Parameters

- `ioValue` — The proposed group name, or `nil`.
- `outError` — On return, an error describing invalid syntax.

## Return Value

Whether the proposed value uses valid kerning group syntax.

## Discussion

This does not check whether the group is used by other glyphs or has kerning values.

## See Also

### Kerning Groups

- [`GSGlyph.leftKerningGroup`](/Core/GlyphsCore/GSGlyph/leftKerningGroup) — Kerning group for pairs on the left side.
- [`GSGlyph.rightKerningGroup`](/Core/GlyphsCore/GSGlyph/rightKerningGroup) — Kerning group for pairs on the right side.
- [`GSGlyph.topKerningGroup`](/Core/GlyphsCore/GSGlyph/topKerningGroup) — Kerning group for pairs on the top side.
- [`GSGlyph.bottomKerningGroup`](/Core/GlyphsCore/GSGlyph/bottomKerningGroup) — Kerning group for pairs on the bottom side.
- [`GSGlyph.leftKerningGroupId`](/Core/GlyphsCore/GSGlyph/leftKerningGroupId) — Prefixed kerning key corresponding to [`GSGlyph.leftKerningGroup`](/Core/GlyphsCore/GSGlyph/leftKerningGroup).
- [`GSGlyph.rightKerningGroupId`](/Core/GlyphsCore/GSGlyph/rightKerningGroupId) — Prefixed kerning key corresponding to [`GSGlyph.rightKerningGroup`](/Core/GlyphsCore/GSGlyph/rightKerningGroup).
- [`GSGlyph.topKerningGroupId`](/Core/GlyphsCore/GSGlyph/topKerningGroupId) — Prefixed kerning key corresponding to [`GSGlyph.topKerningGroup`](/Core/GlyphsCore/GSGlyph/topKerningGroup).
- [`GSGlyph.bottomKerningGroupId`](/Core/GlyphsCore/GSGlyph/bottomKerningGroupId) — Prefixed kerning key corresponding to [`GSGlyph.bottomKerningGroup`](/Core/GlyphsCore/GSGlyph/bottomKerningGroup).
- [`GSGlyph previousKerningGroupForDirection:`](/Core/GlyphsCore/GSGlyph/previousKerningGroupForDirection:) — Kerning group on the side facing the preceding glyph for a writing direction.
- [`GSGlyph setPreviousKerningGroup:forDirection:`](/Core/GlyphsCore/GSGlyph/setPreviousKerningGroup:forDirection:) — Sets the kerning group on the side facing the preceding glyph for a writing direction.
- [`GSGlyph previousKerningGroupIDforDirection:`](/Core/GlyphsCore/GSGlyph/previousKerningGroupIDforDirection:) — Prefixed kerning key on the side facing the preceding glyph for a writing direction.
- [`GSGlyph setPreviousKerningGroupID:forDirection:`](/Core/GlyphsCore/GSGlyph/setPreviousKerningGroupID:forDirection:) — Sets the prefixed kerning key on the side facing the preceding glyph for a writing direction.
- [`GSGlyph nextKerningGroupForDirection:`](/Core/GlyphsCore/GSGlyph/nextKerningGroupForDirection:) — Kerning group on the side facing the following glyph for a writing direction.
- [`GSGlyph setNextKerningGroup:forDirection:`](/Core/GlyphsCore/GSGlyph/setNextKerningGroup:forDirection:) — Sets the kerning group on the side facing the following glyph for a writing direction.
- [`GSGlyph nextKerningGroupIDforDirection:`](/Core/GlyphsCore/GSGlyph/nextKerningGroupIDforDirection:) — Prefixed kerning key on the side facing the following glyph for a writing direction.