omittag

I am currently validating a client's HTML Source and I am getting a lot of validation errors for images and input files which do not have the Omittag. I would do it manually but this client literally has thousands of files, with a lot of instances where the is not . This client has validated some img tags (for whatever reason). Just wondering if there is a unix command I could run to check to see if the does not have a Omittag to add it. I have done simple search and replaces with the following command: find . \! -path '*.svn*' -type f -exec sed -i -n '1h;1!H;${;g;s/<b>/<strong>/g;p}' {} \;