Onenote should recognize commonly used note taking symbols e.g. ↑.

[ward1e]

It would be very useful if onenote could recognize commonly used note taking
symbols when converting handwriting to text. Such as the arrow symbols and
the triangle of 3 dots representing therefore.

 

[Erik Sojka]

That's more of a limitation of the Tablet PC Ink engine than of OneNote
directly.

The best workaround I can recommend is to use the AutoCorrect options to
replace a letter sequence with the character you want. e.g. "uarr" --> "↑"