Remove setting from style to inherit setting from base style

Solution 1:

Turns out there is already an article about this very topic (down to the space-after property being used as an example) available on the word.mvps.org website.

The general idea is you need to use a VBA macro once to clear the formatting. Microsoft Word would benefit from such feature included in the GUI.

Dim oStyle As Style
Set oStyle = ActiveDocument.Styles("Subject")
oStyle.ParagraphFormat.SpaceAfter = oStyle.BaseStyle.ParagraphFormat.SpaceAfter

Solution 2:

This is an old question, but still valid, and the answers given so far are not very practical. A simple way to cancel a definition, that deviates from the "Style based on", is to define the property to be the same as in "Style based on". This will remove the definition completely, because it is then useless.

As an example (and a specific answer to the original question), if your style is based on Normal, check what is the Spacing-After value in Normal style. Then change (Styles->[your style]->Modify->Format->Paragraph) the Spacing-After value in your style to be the same as in Normal style. (As default, at least in Word 2019 this value seems to be 8 pt, so you have to write the number 8 instead of clicking down-up, that goes in steps of 6 pt). After that, the style specific Spacing-After definition disappears.