What does it change for SEO and webmasters?
- Duplicate Content Issues – We have seen multi level drop down menus and option boxes causing Google to crawl and index duplicate content following URL patterns based on the GET strings. One of the advanced optimization technique used by SEOs for work flows is to add static links on the pages to next steps, but use a drop down menu for a better customer experience. For instance the URLs for steps may look like /step1.html -> /step2.html -> /step3.html. However, its counterpart form might generate URLs like /step1.html?v=widget1 -> /step2.html?v=widget1&x=widget2 -> /step3.html?v=widget1&x=widget2&y=submit.
These would certainly create multiple URLs for the same content. Solutions to these may involve adding optional parameters in Google Webmaster Tools (only for Google) or perhaps using POST instead of GET.