| Cconf | Configuration array entry |
| Cconf_entry_val | Configuration array entry value |
| Ccore_article_header | Article header fields supported by core |
| Ccore_data | Structure to transfer data between core and UI threads |
| Ccore_groupstate | Group description |
| Ccore_hierarchy_element | Node in article hierarchy |
| Ccore_range | Article range linked list element |
| Cenc_mime_ct | MIME content type information |
| Cenc_mime_mpe | Locations of MIME multipart entities |
| Cenc_wm_pattern | Wildmat array element (for RFC 3977 wildmat-pattern) |
| Cnntp_groupdesc | NNTP group descriptor |
| Cnntp_grouplabel | NNTP group label (description string) |