How can spell checking be turned off for a portion of a OneNote page

A variation on the language support trick from Petri above seems to do what you want: Select a block of text in your document that you want to disable for spell checking Go to the Review tab and select Language > Set Proofing Language Select a language for which you and your likely readers have no dictionary, e.g. Afrikaans, Cherokee etc. work for me. The other text will still default to being in the original language, e.g. English (UK) in my case and will still be spell checked as normal. You …