Flag for header text to field component that enables or disables merging of data inside components using tags (placeholders).
Tags (or placeholders) are words surrounded by %%on each side. There are data tags and
standard tags. Data tags consist in names of dataproviders surrounded by%%. Standard tags
are a set of predefined tags that are made available by the system.
See the "Merging data" section for more details about tags.
The default value of this flag is "false", that is merging of data is disabled by default.