Ray wrote:
A word like /thier/ can safely be changed to "their", since it's almost always a misspelling. However, there are many misspellings which can't be automatically corrected.
You can never be sure without looking at it in person. Wasn't there a French statesman by that name a century ago? If that's the case the proper correction would be to capitalize. :-)
A quick search on google reveals that, though rare, there is a name 'Thier'. I think this is actually a great example, because it *did* seem so unobjectionable at first glance.
--Jimbo