Stack Exchange userscript for showing spoilers on questions with particular tags
For Loop

The style of the for loop you're using could be improved.

for (var jj = 0; jj &lt; tags.length; jj++) {
    // If we don't find the tag in the array of spoiler-able tags,
    // then we have to reject the question.
    if (SHOW_ME_SPOILERS_IF_TAGGED.indexOf(tags[jj]) == -1) {
        return false;
    }
}


should probably be changed to a for of loop

for (tag of tags) {
    // If we don't find the tag in the array of spoiler-able tags,
    // then we have to reject the question.
    if (SHOW_ME_SPOILERS_IF_TAGGED.indexOf(tag) == -1) {
        return false;
    }
}


map

This code is essentially doing the same thing as a map function:

var tags = [];
for (var ii = 0; ii &lt; hrefs.length; ii++) {
    tags.push(hrefs[ii].innerText);
}


You could rewrite it to this (which uses an arrow function as well):

var tags = hrefs.map(href =&gt; href.innerText);