The content of an HTML element will be parsed in inline mode unless the opening tag is followed by two linebreaks, in which case it will be parsed in block mode. (Inline mode means that block mode formatting such as tables, lists and headings is not recognised).
Transcluded attribute values are indicated with double curly braces around a TextReference. For example:
```
attr={{tiddler}}
attr={{!!field}}
attr={{tiddler!!field}}
```
!! Variable Attribute Values
Variable attribute values are indicated with double angle brackets around a [[macro invocation|Macro Calls in WikiText]]. For example:
```
<div title=<<MyMacro "Brian">>>
...
</div>
```
!! Filtered Attribute Values
Filtered attribute values are indicated with triple curly braces around a [[Filter Expression]]. The value will be the first item in the resulting list, or the empty string if the list is empty.
This example shows how to add a prefix to a value: