ual to 1, and discarding any following (less significant, farther to the right) bits that follow it, which are equal to 0. The data necessary for the decoding process is contained in the SODB part of the RBSP. mulation_prevention_three_byte is a byte equal to 0x03. When an emulation_prevention_three_byte is present in the NAL unit, it shall be discarded by the decoding process. The last byte of the NAL unit shall not be equal to 0x00. Within the NAL unit, the following three-byte sequences shall not occur at any byte-aligned position: 0x000000 0x000001 0x000002 Within the NAL unit, any four-byte sequence that starts with 0x000003 other than the following sequences shall not occur at any byte-aligned position: 0x00000300 0x00000301 0x00000302 0x00000303 NOTE 7 - When nal_unit_type is equal to 0, particular care must be exercised in the design of encoders to avoid the presence of the above-listed three-byte and four-byte patterns at the beginning of the NAL unit syntax structure, as the syntax element remulation_prevention_three_byte cannot be the third byte of a NAL unit. 7.4.1.1 Encapsulation of an SODB within an RBSP (informative) This clause does not form an integral part of this Recommendation | International Standard. The form of encapsulation of an SODB within an RBSP and the use of the emulation_prevention_three_byte for encapsulation of an RBSP within a NAL unit is specified for the following purposes: to prevent the emulation of start codes within NAL units while allowing any arbitrary SODB to be represented within a NAL unit, to enable identification of the end of the SODB within the NAL unit by searching the RBSP for the rbsp_stop_one_bit starting at the end of the RBSP, to enable a NAL unit to have a size larger than that of the SODB under some circumstances (using one or more cabac_zero_word). The encoder can produce a NAL unit from an RBSP by the following procedure: The RBSP data is searched for byte-aligned bits of the following binary patterns: '00000000 00000000 000000xx" (where XX represents any