A major challenge here at the forum is deciding into which forums to post new threads. We separate out topics into logical subforums to the best of our ability, but many threads address more than one core topic.
The standard way to deal with that problem is to use "tags" when setting up threads (there's a box for that when you start a thread). It's also possible to simply include in the body of a post a hashtag like #Ethics, which the system will then be able to find automatically when searching by tag.
The problem with tags, however, is that over the years we've developed a multitude of single-use hashtags that overwhelms the system, and it becomes impossible to use such a large number of tags productively.
Today I've done a massive culling of years of single-use tags that lead nowhere, and cut the master list down to those you see here on the page entitled Tags Overview (also known as Complete Tag List).
We encourage the use of the standard tags as people create new posts and edit old ones. Words that occur only once or very few times are best left for individual searches using the search box, but we'll build lists of the key tags over time as a navigation aid. Let us know if we important tags are missing (almost certainly we need more) but we'll continue to curate them over time to make sure the number doesn't explode as in the past.