This attribute is a variable length series of hexadecimal octets where each series entry consists of the following fields (encoded in the following order): - The ifIndex (4 octets) of the OFDM channel where the downstream Profile IDs are assigned. - The number or count of Profile IDs (1 octet with valid values of 1-4) assigned to the CM on that channel. - The list of Profile IDs (1 octet each with valid values of 0-15) assigned to this CM on that channel. Profile ID 0 is commonly referred to as Profile A. Likewise, Profile IDs 1, 2 and 3 are commonly referred to as Profiles B, C and D. The CCAP encodes each OFDM channel in a CM's RCS as a separate n-octet entry in the ProfileIdList. Examples: a CM with a single OFDM channel (ifIndex 34) and four assigned profiles (Profile IDs 0, 8, 9 and 10) would have a ProfileIdList value of 0x00000022040008090A. A CM with a 2 OFDM channel bonding group each with two assigned profiles (Profile IDs 0 and 15 on channel with ifIndex 34 and Profile IDs 0 and 14 on channel with ifIndex 35) would have a ProfileIdList value of 0x0000002202000F0000002302000E). Note: the CCAP must not include the transitional profile or test profile in the ProfileIdList. Note that octet string lengths greater than 18 are optional. This object is applicable to DOCSIS 3.1 modems but not to prior versions of DOCSIS modems. If the CM is a pre-DOCSIS 3.1 modem, the CMTS returns a zero length octet string.