YouTube Video IDs

YouTube video IDs are indeed unique strings that identify each video, but they can include hyphens ("-") along with letters, numbers, underscores ("_"), and other characters. The video ID typically consists of 11 characters and can include a mix of:
- Uppercase letters ("A-Z")
- Lowercase letters ("a-z")
- Numbers ("0-9")
- Special characters like hyphens ("-") and underscores ("_")

For example:
- A valid YouTube video ID might look like "dQw4w9WgXcQ" or "abc-def12345".

So, hyphens are allowed and can be part of a video ID.