What are some off page SEO mistakes?

Hello friends,

What are some off page SEO mistakes?

Hi Friends,
Common Off-Page SEO Mistakes
-Buying Links
-Comment Spamming
-Article Marketing
-Directory Submissions
-Targeting Wrong URL

- Irrelevant content pages
- Link farming
- Hidden links

1) Duplicate Content.
2) Broken Images and Missing Alt Tags.
3) Using Nofollow Tags to Hide Pages.
4) Poor Quality External Links.
5) Poorly Structured Internal Links.
6) Slow Page Loading Speed.
7) Poorly Optimized Title Tags and Meta Descriptions.

1. duplicate content
2. buying links
3. hidden content
4. mirror websites
5. keyword stuffing