difficult to find | the next to highest level of official classification for documents |
not accessible to view | not open or public; kept private or not revealed |
designed to elude detection | having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding |
| not expressed |
| (of information) given in confidence or in secret |
| not openly made known |
| conducted with or marked by hidden aims or methods |
| designed to elude detection |
| indulging only covertly |
| hidden from general view or use |
| communicated covertly |