Creating Microdata

Microdata can only be applied to an existing text selection or element.

1. Select the text or element to apply the microdata on.
2. Click on the Insert / Edit Microdata button 
3. After a short delay while the Microdata schema is retrieved from http://schema.rdfs.org the Types list will be populated with the available Microdata Types, and enabled.
4. Select the required Type from the list, eg: Article. This relates to the itemtype attribute - "A valid URL of a vocabulary that describes the item and its properties context"¹ - and will be applied to the selections parent element (eg: paragraph)
   
5. Select the required Property from the list. This relates to the itemprop attribute - "Indicates that its containing tag holds the value of the specified item property. The properties name and value context are described by the items vocabulary. Properties values usually consist of string values, but can also use URLs using the a element and its href attribute, the img element and its src attribute, or other elements that link to or embed external resources"² - and is applied to the selected element or text.
   
6. Add the optional itemid if required by entering the value into the Id field.
7. Click the Insert button.

Editing Microdata

Existing Microdata can be edited or new nested Microdata added to the selection by following the same steps as above. When editing Microdata, select Replace / Update to change Microdata on the selection, or New to add nested Microdata to the selection.

Removing Microdata

1. Select the element or text that has microdata applied to it.
2. Click the Insert / Edit Microdata button.
3. After a short delay while the Microdata schema is retrieved from http://schema.rdfs.org the Types list will be populated with the available Microdata Types, enabled, and the active Microdata Type selected.
4. Select -- Select Type -- (the first item) from the Type list.
5. Click Update.

References

1.  http://en.wikipedia.org/wiki/Microdata_(HTML)
2.  http://en.wikipedia.org/wiki/Microdata_(HTML)