I noticed that CC-CEDICT uses a mixture. For example:
mian4: 前面, 对面, 里面
mian5: 后面, 上面, 下面, 外面
ABC is similar except:
mian4: 后面 (but also has mian5 as a less common pronunciation)
mian5: 前面
Is there any standard for these? Is it reasonable that the same dictionary would have a mixture like these do?
Baidu Dict has all 面 as 4th tone.