Word Tip: Customize Spelling & Grammar Tools
When you set a word or phrase to be ignored by the spelling and grammar checker, it is ignored if you run the spelling and grammar checker later, whether the spelling and grammar are correct or not. If you want to change your mind and want ignored text to be checked instead: First, select Tools/Options (Preferences on the Mac) from the menu bar, and then click on the Spelling & Grammar tab. Next, click the Recheck Document button at the bottom of the dialog box.
When prompted to continue, click Yes. This removes the "ignored" status from any items you chose to ignore during an earlier spelling or grammar check. Click OK to close the Options (or Preferences) dialog box, and then run the spelling and grammar checker to recheck the document.
Note: In order for the technique described above to work correctly, Word must be configured to check spelling and grammar as you type. To check Word's spelling and grammar settings, select Tools/Options (Preferences on the Mac) and click on the Spelling & Grammar tab. Make sure the Check Spelling As You Type and Check Grammar As You Type check boxes are selected. In addition, make sure that the Hide Spelling Errors In This Document and Hide Grammatical Errors In This Document check boxes are cleared. When you've finished, click OK.