Property Syntax (The Org Manual).
You may define the allowed values for a particular property ‘Xyz’ by setting a property ‘Xyz_ALL’. This special property is inherited , so if you set it in a level 1 entry, it applies to the entire tree. When allowed values are defined, setting the corresponding property becomes easier and is less prone to typing errors.
这一段,没懂
比如我这样写
* test
:PROPERTIES:
:ORDERED_ALL: t
:END:
** test2
test2是继承了这个order t的属性吗? 但是好像测试了一下也没有啊。