Direct mail is a broad term that includes the following types of mailed promotions: Institutional direct mail serves to promote the name of the publishing house with no reasonable expectation of sales revenues.
touch (Unix) touch is a standard Unix command-line interface program which is used to update the access date and / or modification date of a file or directory. In its default usage, it is the equivalent of creating or opening a file and saving it without any change to the file contents.
While unix-line-discard is a good mnemonic, the use of CTRL+U as a line-erase character precedes the invention of UNIX. It was used as such on various Digital Equipment (DEC) systems, including the PDP-8. For instance, from my dusty bookshelf I see that CTRL+U was used as line-erase in the PDP-8 Symbolic Editor (page 5-13 of the 1972 edition of the PDP-8 Introduction To Programming (Volume 1) manual published by DEC). In fact, in the early days of UNIX, the @ character was often the default line-erase character.