Hard Line Important
Lurking diggers
I found this
Hard-Line
Entrance Warning
Entry Alert
Overview
How Does it work?
EntryAlert™ is an entrance warning system for both remote operators and mine personnel.
Mine personnel are alerted that there is a remote machine in use in a stope through the use of a strobe light at the entrance to the work area. The remote operator is alerted that personnel have entered his work area through the strobe light in the remote operator’s station.
http://www.hard-line.com/entrance-warning-remote-control/
digging
CHANDED code SOS warning
hard-line adjective
\ˈhärd-ˈlīn
\
Definition of hard-line
: advocating or involving a rigidly uncompromising course of action
History of Hard Lines
Hard lines
What's the meaning of the phrase 'Hard lines'?
Bad luck.
What's the origin of the phrase 'Hard lines'?
A line can be many things - a cord or string, a linear mark, a short letter, a policy, a range of retail goods, and so on. Given that, and the fact that 'hard lines' isn't obviously derived from any one of them, the door is open for the merchants of conjectural etymology.
https://www.phrases.org.uk/meanings/hard-lines.html
The bombing hoax is distraction to show how stupid people are.