I know the 8.3 short name was the max length of a file name in DOS.\nabcdefgh.xyz\n\n\nIt carries through to Windows 8, although obviously no longer a requirement.\n\nI never gave thought to its use in batch (or other languages calling a shell) until early this morning, i.e., whether the shortening of a name to include a tilde ~ in a folder or filename flowed through or not (if not used on purpose) -\n\n\n\n\nThe CMD screen shows the 8.3 file name for my laptop here as I was accessing the TEMP dirs - Microsoft Windows [Version 6.1.7601]\nCopyright (c) 2009 Microsoft Corporation. All rights reserved.\n\nC:\\Users\\PalmDesert>echo %temp%\nC:\\Users\\PALMDE~1\\AppData\\Local\\Temp\n\nC:\\Users\\PalmDesert>cd appdata\\local\\temp\n\nC:\\Users\\PalmDesert\\AppData\\Local\\Temp>\n\nNothing surprising there, but the other portion of the screenshot is from SysInternals Process Monitor. \n \n\nI've never seen an 8.3 name in ProcMon before. Could the app it passed through have an issue with the ~ ? I know that batch may in FOR loop or other unexpected place it shows up.\n\nWhy would C++ or other modern language be using the 8.3?\n\nWhat does %~d0 mean in a Windows batch file? - Stack Overflow\n\nThis is not a rhetorical question! I honestly do not know.