It is recommended that the site owner represent the term 'free traffic' with asterisks or other special symbols, just like the words 'ma' and 'cao'. Otherwise, friends who want to request free traffic might be afraid to post a request. If someone from the mobile network dials 7723 and happens to see a post requesting free traffic, the free traffic might be blocked.
This is just a personal suggestion, hoping the site owner will consider it.
