ETERNAL RDC-Arq repository uses UTF-8 as its main character encoding. 
UTF-8 is an encoding system for Unicode. It can translate any Unicode character to a matching unique binary string, and can also translate the binary string back to a Unicode character. 

ETERNAL RDC-Arq AIPs are stored on multiple storage systems that include different sets of hardware technologies, with the goal of preserving AIPs for the long-term. Most technologies have proprietary bit encoding and decoding formats, and for each technology a future user must consider the existence of the appropriate tools to read and decode binary streams before AIP access is possible. ETERNAL RDC-Arq has an extra layer of storage to a hardware defined as NDAS (Non-Destructible Archival System), that uses the standard of eight bits, as documented in ISO/IEC 2382-1:1993, which is a convenient power of two permitting the binary-encoded values 0 through 255 for one byte, as 2 to the power of 8 is 256. The international standard IEC 80000-13 codified this common meaning.

The NDAS is a direct laser writer that works with a single laser beam to create high-resolution indentations on the information carrier hardware. The reliability, low-maintenance laser writer combined with a Silicon Dioxide (SiO2) pretreated substrate provides a data archival solution for a minimum of 1,000 years.