Permanently Removing Blue Squiggly Underlines

As well as supressing grammar error underlines it is often desirable to supress spelling error underlines because there maybe proper nouns or the client may be using a different language or English version.

Setting NoProofing for the whole document will prevent any error underlining being displayed and the 50 paragraph limit makes it difficult for the client to overrule. A further advantage is that the document opens quicker because the spell checker has nothing to work on.

Thank you Ken Endacott - I was unaware of that 50 paragraph limit, and it does explain some erratic behaviour I've seen in the past.

There is a good solution available if the document uses styles that are based directly or indirectly on one master style, e.g. the Normal style (or equally, if the author hasn't intentionally applied styles at all, so the whole document is in the Normal style plus direct formatting). In that case you can turn off proofing for the whole document at once, regardless of how many paragraphs it has, by modifying the Normal style: on the Home tab, right-click on the master style in the Styles Gallery (or if it's not there, click the arrow in the bottom-right corner of the Styles pane and find it in the full list of styles) then select Modify -> Format -> Language -> Do not check spelling or grammar.

In principle you can easily reverse this change in order to check for spelling mistakes in the finished document then reapply it to hide the blue squiggly underlines. In practice you might notice that these changes don't take effect immediately, e.g. after re-enabling proofing you have to select File -> Options -> Proofing -> Recheck Document before any spelling errors show up. So it might be worth creating macros for turning proofing off and on in this way.

It is possible to use NoProofing to achieve what Marie wants.

NoProofing settings travel with the document and prevent spelling and grammar checking irrespective of the settings of the client’s system. To apply NoProofing to selected text:
Review > Language > Set Proofing Language and tick Do not check spelling of grammar.

There are some issues.

It may be required that spelling errors should be displayed but not grammar errors, however NoProofing prevents both spelling and grammar checking. This can be overcome by applying NoProofing only to words or phrases that raise grammar errors and hopefully contain no spelling errors.

It is not obvious where in a document NoProofing is set. This can lead to puzzlement when spell checking works in some parts of the document but not others.

There is a maximum of 50 paragraphs at a time that can be set or unset, if a large block of text is to have NoProofing applied then successive 50 paragraph blocks must be set. If you try to set or unset more than 50 paragraphs at a time, nothing happens and Word does not tell you that the action has failed. If you want to clear all NoProofings in a document it must be carried out 50 paragraphs at a time, somewhat impractical for large documents unless you use a macro.

Another possible (but not fully tested) solution is to switch off spelling and grammar checking for the offending text. Select the text (it doesn't need to be a whole sentence). From the ribbon select Review, then Languages, Set Proofing Language ... set Do not Check Spelling or Grammar.

I'm not able to test this across systems but, under testing, "Do not Check Spelling or Grammar" is maintained between closing and re-opening the file.