Currently, if doing an
```
insource:/foobar/
```
search with AWB (all namespaces), we get massive lists of mostly article-related things, for example [[https://en.wikipedia.org/w/index.php?search=insource%3A%2Fbibcode%2F&title=Special:Search&profile=advanced&fulltext=1&searchToken=bk8mre9j5wy6cf0r6livhjsj3|this]], and we run into API limits of 1000 results per search or whatever.
It would be very useful if we could apply namespace filtering BEFORE the search, [[https://en.wikipedia.org/w/index.php?search=insource%3A%2Fbibcode%2F&title=Special:Search&profile=advanced&fulltext=1&ns4=1&ns6=1&ns7=1&ns8=1&ns9=1&ns10=1&ns12=1&ns13=1&ns14=1&ns15=1&ns100=1&ns101=1&ns108=1&ns109=1&ns118=1&ns119=1&ns446=1&ns447=1&ns710=1&ns711=1&ns2300=1&ns2301=1&ns2302=1&ns2303=1&searchToken=rxuonkn3exnen1cx62c9qs8n|like this]], so we don't run into API limit issues as often when searching for things outside of mainspace.