Individual List:

1. CSS does not use < >
2. Line 20 - there is no display: diamonds
3. Line 25 - uses [ bracket instead of {
4. Line 27 - uses wrong bracket
5. Line 63 - Body with background color is labeled twice

Group List:

1. Main is inside <> opening tags doesn't need to be
2. Body has brackets instead of curly braces
3. 4 either needs to be a class or id. Specific mark is missing
4. The explanation mark needs to be inside note-Cntrl /
5. Main has html closing tags, just needs bracket
6. Diamonds isn't a correct display type
7. Two headers labeled .header nav a
8. Margin bottom has no unit
9. Margin top has no unit
10. Padding left has no unit
11. Padding right has no unit
12. H2 height is spelled wrong
13. Body with background color is labeled twice
14. The header nav active should be at the top
15. Header nav visited should be at top
16. Background color in menu-icon is spelled colour
17. One header is displayed as id div instead of class
18. Body is in between the header nav info