Use tags: have them display as tags; have them function as tags, e.g., in the attached image none of the tags display as tags; three of the items entered as tags do not appear in the tags list.
Tags have to start with #. It would be nice if Obsidian recognized that ( isn’t part of it, but I suspect that other apps and services that support hashtags might not do that, so the way Obsidian behaves now is likely to be more compatible.
When I went to correct my entries I discovered why I was getting this result: I started the tagging inside parentheses instead of with a hashtag. Dunno why I did that. If you start with a hashtag Obsidian adds the initial space to the tag.