PropertyHandle :: IsReadOnly - Is property read only
There are several reasons for properties getting the read-only state. An attribute is read-only when the instance it belongs to has been set to read-only for some reason (used by another user, cannot be updated by current user or others). Collections are usually set to read-only when the instance the collection belongs to has been set to read only, but they might also be persistent write protected (e.g. when being locked in workspaces). Since MEMO fields are stored as separate instances, a MEMO field can be read-only even though the parent instance can be updated (e.g. when being locked in a transaction). Moreover, any property can be set to read-only by means of the context function SetReadOnly() in the application.
Attributes and MEMO fields with read-only state cannot be updated. Collection properties that are read-only do not allow inserting, renaming or removing instances from the collection.
The function returns YES when the question was answered positively. Otherwise it returns NO.