This option lets you add and manage your unique meta data in order to show search engine users what your site is about before entering it. Having unique meta data can help improve you site's Search Engine Optimisation (SEO) and Search Engine Results Page (SERP).

To access Document Properties:

1. Open the document that you want to make changes to. 
2. Click the 'File' option from the menu bar at the top of the editor window. A drop-down menu will appear.
3. Click 'PROPERTIES' to open the 'DOCUMENT PROPERTIES' dialog window (above image).
4. Enter any relevant details
5. Click 'Apply' to save changes
   
   

What does each field mean?

Page Title: This will appear as the title above your description when your webpage appears in search results. The optimum amount of characters for a Page Title is 50 - 60 characters. If there is no Page Title then the document's 'Description' will be the default title.

Meta Description: This will be the description that appears below your Page Title, when your webpage appears in search results and should concisely describe what the page is about. The optimum amount of characters for a Meta Description is 155 characters. If there is no Meta Description then the search engine will attempt to summarize the page itself.

Meta Keywords: Meta Keywords are a list of your page's keywords, separated by commas, that will only appear in the backend code of your website. Please note that this field becomes less vital to SEO as new search algorithms are rolled out. The optimum number of Meta Keywords is 10 words (Any more than that and you may be penalized!)

Additional Code: This is a developer tool, whereby you can enter any additional supporting data in the text area (e.g. CSS, JavaScript).

On Load Events: Another tool for developers -  On Load Events is most often used within the element to execute a script once a web page has completely loaded all content (including images, script files, CSS files, etc.).