Well.... technically JLCR, as well as some of your examples, aren't acronyms either. They're initialisms.
An Acronym is a shortening of multiple words (not always the first letter) into one "word" that is pronounced as a word and not letters. Examples are NASA, RAM, and LASER.
An Initialism is taking the first letter of each word and pronouncing the letters, such as FBI, USA, DVD, and ATM.
An Abbreviation is a single word that is reduced to make it fewer letters, such as Dr. or St.
I suppose NAR could either be pronounced as an initialism, "En Aye Are", or as an acronym, "Naar", and people here would know what you meant. I'm not sure if LDRS is ever pronounced as "Elders" or not.
Edit: Kallahan11 beat me to it by a few minutes.