This is a simple set of properties that can be shared across many simple applications. ~~~ ~usage~ A descriptive note giving examples of how a descriptor should be used. ~~~ ~content~ Constraints and instructions on the value for a specific descriptor. ~~~ ~url~ The value contains a url for the parent attribute. ~~~ ~id~ The identifier for the description or part of a description. The description identifier must be unique within at least the service providing the description. A descriptor identifier must be unique within the text stream. ~usage~ | ~id~ identifer | Item~ | ~id~ item1 | title~ Hamlet | etc~ ~~~ ~service~ A partial url which when containing the identifier provides access to the description. The position of the identifier is marked by {identifier}. An external reference to a specific descriptor within the text stream comprises the ~id~ of descriptor appended to the text stream ~id~ as follows : {text stream ~id~}#{descriptor ~id~} A text stream may be provided by more a than one service so there may be several values for this. ~usage~ | ~id~ identifer | ~service~ Oldieshome example service | ~url~ https://oldieshome.org.uk/descriptions?id={identifier} ~~~ ~created~ The value is the date and time the description was first created. ~content~ All date and time properties should use the same format based on ISO ???? . ~~~ ~updated~ The value is the date and time the description was updated. ~~~ ~version~ A version number or statement for description. ~~~ ~language~ The language used in the text stream. This is not the same as the language appearing in the entities described in the text stream. Use language~ for that purpose. The value may be either the code or the language name specified in ????. ~~~ ~note~ A note about the act of creating or updating a descriptor, the value's source and some specific aspect of the value. ~~~ ~by~ The person or other agent responsible for an action. ~usage~ For example associated with an update : | ~updated~ 2019-08-31T10:37:56 | ~by~ Bill Oldroyd | ~note~ Correcting spelling mistakes