I can guess what they signify, but they are hexadecimal values; a base 16 number system rather than a base 10 (decimal) system you're used to seeing.  In "Hex", each two character pair represents an 8-bit integer from 0-255. Each character represents a "nibble"- a 4-bit value from 0-15, or 0-1-2-3-4-5-6-7-8-9-A-B-C-D-E-F.  Where A=10 and F=15.  You can compute the value of B4 as 11*16+4=180.  10 would be 1*16+0=16. 1F would be 1*16+15=31.  Etc.  These might be checksums to assure the right code was downloaded for 6 updates.