Search hidden tag feature request

Let’s say I have the ‘caption’ tag hidden, but I want to make a search that includes it.
 
The idea is that:  
if you precede the term with plus sign then it is included in the search results (un-hidden)  
if you precede the term with a double plus sign then it is treated as a tag to search
 
fluttershy, +caption = returns everything tagged fluttershy including fluttershy with caption
 
fluttershy, ++caption = returns everything tagged fluttershy and caption
 
 
A single plus sign ought to make spoilered tags visible as well.
 
fluttershy, +animated = un-spoilers ‘animated’