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.
The touch command is the easiest way to create new, empty files. It is also used to change the timestamps (i.e., dates and times of the most recent access and modification) on existing files and directories. touch's syntax is. touch [option] file_name(s)
DTMF Touch Tones are defined in CCITT Volume VI: General Recommendations on Telephone Switching and Signalling Recommendation Q.23: Technical Features of Push-Button Telephone Sets.. This document and its related standard documents will tell you more than you would ever want to know about DTMF tones.