- general concept of tag based visibility control
Tag is a bridge between webpages and the elements on the pages. In Deco Site Editor, tags are used to manipulate the display conditions of elements.
Not all characters or symbols are accepted as the name of tags, only the strings consist of letters, numbers and the underscore are recognized.
A single page can contain more than one tag, such as "wedding gallery"; similarly an element can contain multiple tags, all tags are separated by comma and the tag name is case-insensitive.
 
- set page tags
For the tags of a page, you can input the qualified texts into the "Tags" field of the page properties.

- set element display conditions
For the elements, you can define their display condition through Layout tab>Display Condition
All element can be defined as "Always Display" or "Match Tagged Pages".
 
When the page transition takes place, the tags will take effect to control the display of elements on page.
If an element is defined to be "Always Display", it will be displayed on the webpage unconditionally.
If an element is defined to be "Match Tagged Pages" and certain tags a specified for the element, the element will only be displayed when any of its tags matches one of the page tags.