Hi Omer,
I enjoy this macro! It is, as people have noted, very useful for programmers. Awesome!
The cursor seems to become invisible if i click inside the selection right after running the "No Spell Check" macro. If i click outside the selection first and then inside the previous selection, then the cursor is visible. Just an FYI if you ever look at this one again.
(and as always YMMV!)

How can I check the spell for my whole Notebook? thanks!

I think you work on the 1N development team. Please pass along this SUGESTION: Customize QAT (Quick Access Toolbar), Include the "settings" commands to toggle on/off GLOBAL setting(s) which ARE NOT listed in QAT customization procedure.
      [x] Hide spelling and grammar errors
When I switch to a different page, to ENABLE the setting to resume automatic detection I must -->   File / Options / Proofing / "toggle" checkbox - which is inconvenient & counter-productive.
I write my ideas, code outline, in pseudo C# syntax and do not want to "add words to custom dictionary" and use 1N a lot!  Switching from page to page I want the detection to be easily toggled. Possibly this (as well as "other" settings) should be considered as a 1N enhancement. Thanks in advance!  - OneNote is incredibly awesome.

Nice macro, exactly what I was looking for to use with code.   Would be nice if I could somehow tie this to a formatting style.

Thanks for this macro!
Now I can Alt+A to select everything in the page then remove the spell check! comes in handy for every programmer.

A great macro if you are adding any kind of code to your OneNote page and want to turn off those annoying red squiggles! Works great!

This macro is not convenient for non-English Users or bilingual user.
If you don\'t select any text and run this macro, the proofing got changed to English Proofing instead of maintaining original non-english proofing.

If you select text and run this macro, the proofing got changed to African Yoruba Proofing which we seldom use but do remove red squiggles.