Defining topic keywords for searching purposes

I wish to define keywords for each topic and use them during searching (WebSearch).

I strongly believe that it is possible through defining variable (for example keyword) in topic preferences and playing around SEARCH macro.
However, I can't find any 'ready' or 'recommended' solution. I would imagine that there might be (functionality? plugin?) which display any field to define keywords.

Something like this can be done using DataForms. There are examples of this in our Tasks web. Attach a form to each topic, and have a keywords field within that form. You can use Ajax to auto-complete keywords from a list for example as well. The Item "Component" field is an example of that.

The query search can easily search formfields.

Another option might be the TagMePlugin, TagsPlugin, TagCloudPlugin ... there are several though I haven't used any of them myself.

-- GeorgeClark - 02 Jan 2015