File encoded in the .UUE format and saved with the generic ".enc" extension; often encoded by a specific program, such as IBM Lotus 1-2-3 or Adobe Flash; protects the file from being opened by unauthorized users.

Navigational chart format used by the Office of Coast Survey (OCS); also referred to as NOAA ENC files, which stands for "National Oceanic and Atmospheric Administration" (NOAA) "Electronic Navigation Chart" (ENC) files.

The NOAA ENC file format is defined by the International Hydrographic Organization S-57 standard. ENC data is used to support marine transportation infrastructure and coastal management.

NOAA ENC files are saved as a database of chart features. Information saved in an ENC file includes the location of each chart feature, as well as attributes such as color, shape, depth, etc.

Copy-protected .PDF file created with CopySafe PDF software; prevents images and text from being copied and protects against Printscreen and screen capture commands; may also include printing protection, password protection, and date expiration.