| 3.1 Syntax |
| @namespace case-insensitivity |
| pass | pass | fail | pass |
| duplicate @namespace declarations |
| pass | pass | fail | pass |
| @namespace syntax with escapes |
| pass | pass | fail | fail |
| string comparison (no URI resolving) |
| pass | fail | pass | pass |
| @namespace default namespace syntax |
| pass | pass | pass | pass |
| whitespace and comment handling |
| pass | pass | pass | fail |
| @namespace url() with escape |
| pass | pass | pass | pass |
| @namespace error handling |
invalid | pass | fail | fail | fail |
| @namespace string and url() syntax |
| pass | pass | fail | pass |
| @namespace and invalid at-rules |
invalid | pass | pass | fail | fail |
| invalid ordering of @namespace and @import |
invalid | pass | pass | fail | fail |
| invalid URI |
| pass | pass | pass | pass |
| @namespace and @charset |
| pass | pass | fail | pass |
| escapes in prefix |
| pass | pass | pass | pass |
| escaped vertical bar in qualified name |
| pass | pass | fail | pass |