Consider an artifact as a document with only textual values:

• for scalar fields (text, string, float, int, etc)
• for list fields, their label is indexed
• for attachment, index their content

As if we indexed the rendered artifact view

From a permission point of view, only fields viewable by "all_users and registered_users" would be indexed. There should be a site admin option to decide whether the threshold is "all_users" or "registered_users".

When a tracker admin update a field value (list field) the whole tracker is re-indexed.

Be careful about shared list fields