create clickable index list

What do you mean with “all the search items” exactly?

If you’re talking about the search results page, then yes, you can modify that as you wish and display it in the format you like.

If you’re talking about the contents of the Relevanssi index, that’s just a very big list of individual words, and would not be particularly helpful as a clickable list.

Thanks for the super-fast reply, Mikko!
My client has asked me to create an index, something like a book index, of a very text heavy blog site. I was looking for a means to automate the process and I knew, from using the excellent Relevanssi plugin before, that it creates an index that might be used in this way, but I didn’t know if that index could be displayed as a clickable list i.e. if you were looking alphabetically for the word ‘chocolate’ you could find it and each reference to the word would be clickable to the location of that word in the blog. Is that realistic?

You can certainly use the Relevanssi data to find all the posts that have the word “chocolate”. Relevanssi doesn’t know the location, but you can use Relevanssi highlight all the words “chocolate” from the post, which helps.

However, book indices contain a very small fraction of the words in the book, carefully chosen only to list the most significant words. The Relevanssi index has ALL the words on the site. You can’t just take the Relevanssi index; it would be very unhelpful. You probably don’t need to know which posts have the word “need”, “example”, or “unhelpful” in them, for example.

If you create the list of words in the index yourself, you can then use the Relevanssi index to find out which posts contain the word.

Yes I see the problem. I had thought of using the STOP words to remove the less important words. But actually there would be tens of thousands of them, so that idea is flawed. Your ideas have been very helpful. I will bring them back to the client for further discussion. Thank you for you thoughtful and prompt advice. It’s much appreciated.

As someone who has built both kinds of indices, the stop words are a good start but not nearly enough. To have enough stop words for a good index would start hurting the search performance.