from https://www.betaarchive.com/forum/viewtopic.php?t=26026
en_7601.17S14.101119-1850_x64fre_enterprisen_en-us_VL_UPG_OEM_EnterpriseN-GRMCNENXVCCP_EN_DVD.iso
en                   Language of the OS. Always two letters (with one exception).
                     Example: en, en-gb, cs, da, no, sv.
                     
7601.17514           Minor version build of the OS.
                     
101119-1850          Compile date of the OS (not of the ISO). Indicates YYMMDD-HHMM.
                     
x64fre               Platform architechture and target.
                     x86 = 32bit 8086-based
                     x64 = 32bit 8086-based with 64bit AMD-64 extensions
                     fre = Free, for end user
                     chk = Checked, debug version
                     Examples: x86fre, x64chk.
                     
enterprisen          SKU version. Examples: enterprise, enterprisen, professional,
                     starter. (The "N" flag indicates the version does not
					 force install of Windows Media Player, per European court
					 ruling.)
                     
en-us                Full language tag of the OS. Must match (1). Examples: en-us,
                     en-gb, sv-se.
                     
VL                   Volume license identifier. Optional.
                     
UPG                  Upgrade identifier. Optional.
                     
OEM                  Original equipment manufacturer identifier. Optional.
                     
EnterpriseN          Matches (5).
GRMCNENXVCCP_EN_DVD  Volume label of the mounted ISO volume. Contains various
                     codes to identify language, SKU, volume/OEM and media.
en_windows_7_enterprise_with_sp1_x86_dvd_u_677710.iso
en              Language of the OS. Always two letters (with one exception).
                Example: en, en-gb, cs, da, no, sv.
windows_7       Product name. Examples: windows_7, windows_8,
                windows_server_2012.
enterprise      SKU version. Examples: enterprise, enterprisen, professional,
                starter.
with_sp1        Integrated service pack level. Optional.
x86             Platform architechture and target.
                x86 = 32bit 8086-based
                x64 = 32bit 8086-based with 64bit AMD-64 extensions
                chk = Checked, debug version
                Examples: x86, x64chk.
dvd             Storage media
u               Update flag. The ISO was updated with some critical patch.
677710          Unique MSDN/Technet image number ID.
en_SW_DVD5_Win_Pro_N_7w_SP1_32BIT_English_-2_MLF_X17-59635.iso
en              Language of the OS. Always two letters. Example: en, cs, da,
                no, sv.
SW              ?
DVD5            Single or double layer DVD. DVD5 = 4.7GB
Win             Product name. Win = Windows.
Pro_N           SKU version. Examples: Pro, Pro KN, Ent.
7w              7 With. Means it's an integrated installation with a service
                pack. Combined with next for full service pack level
                information. Optional.
SP1             Integrated service pack level. Optional.
32BIT           Platform target. 32BIT = x86, 64BIT = x64.
English         Language of the OS.
-2              ?
MLF             Microsoft Licensing Fulfillment
X17-59635       Microsoft Part Number as it appears on the physical
                installation media.