Some it's as easy is cutting off a phone plug and soldering another connector type on, others can be more technical, then again most don't work anymore (except in remote locations) and some are generally just myths (like the Blotto Box), better off about learning about the phone system before you learn how to use little circuits that affect this system.
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"Remember how much fun you had shooting spitwads at the teacher in seventh grade? Imagine applying that kind of attitude to actually fucking with Mitsubishi!"
- Jello Biafra