For the CVs/resumes that have separate skills sections where they just have that bulleted list, I’ve see a few where people explicitly list their skill level. The most visually pleasing one I saw doing this rated all the skills using a row of four circles, and rating each skill - here’s a blog post that’s critical about these types of skill ratings. I’m not as critical of this trend - I take it with a grain of salt when reviewing the resume (similar to how if someone says they’re an “expert” in something, they usually aren’t the creator of the tech or haven’t written a book on it). I’ve also seen the lists split into categories of expertise.
Personally, I don’t have the skills block (I figure if they’re scanning for keywords, that’s automated and it doesn’t matter if it’s separated or not, a computer will easily determine whether I used the keyword or not). In the past roles/accomplishments/etc, I tend to describe what I did and what technologies I used, so the minimum bar for something ending up on my resume is that I have a working knowledge of the tech.
As @deasa and @amy.hoad both state, if it’s on your resume, it’s fair game for someone to ask a question about, so that’s another bar I use - i.e. “would I be comfortable talking about this if someone asked me about it?” One of my favorite questions as an interviewer is to pick out one of these items from someone’s resume and ask questions like “So how did you use python in implementing the dashboard?” It’s a good way to get both an idea of how much they know about the tech, as well as if they BS or not.