Bing AI helped write this code that deletes Microsoft Word styles that are not in use in the active document. Other solutions on the web tend to only act on styles not in use in the main body of the document, and therefore they delete styles used only in footnotes or headers or footers. This version checks all StoryRanges to see if a style is in use, including footnotes, endnotes, headers, footers, etc.
Sub DeleteUnusedStyles()
Dim oStyle As Style
Dim oRng As Range
Dim bInUse As Boolean
For Each oStyle In ActiveDocument.Styles
'Skip built-in styles
If oStyle.BuiltIn Then GoTo Skip
'Check if style is applied to any text in any story type
bInUse = False 'Initialize flag
For Each oRng In ActiveDocument.StoryRanges 'Loop through all story types
With oRng.Find 'Use Find method to search for style
.ClearFormatting
.Style = oStyle.NameLocal 'Set style name as criterion
.Text = ""
.Forward = True
.Wrap = wdFindStop
.Format = True
If .Execute Then 'If style is found, set flag to True
bInUse = True
Exit For 'Exit loop if style is found in any story type
End If
End With
Next oRng
If bInUse = False Then 'If style is not in use, delete it
'Show status message
Application.StatusBar = "Deleting style: " & oStyle.NameLocal
oStyle.Delete
End If
Skip:
Next oStyle
'Restore the default status bar
Application.StatusBar = False
End Sub