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.