Calling toll-free numbers from a cell (mobile) phone
 

My google-fu is lacking this morning. I tried a few different searches but did not come up with a good, comprehensive list. The Wikipedia page is lacking.

I am trying to find a list of countries where you cannot call an in-country toll-free number from a cell phone (mobile phone for most of the world). Anyone know of a comprehensive list?

As an example, Wikipedia has a couple of listings:

• Brazil - Many toll-free numbers are not available from cell phones (usually blocked by the cell phone provider rather than the provider of the toll-free number in an effort to prevent low-price competition from calling card providers).
• In the UK, Freephone numbers are usually only free when calling from a landline.

WebEx has this pdf.
https://www.webex.com/pdf/tollfree_restrictions.pdf

Thanks