Notarikon is used on this site as a technical term in conversations concerning sensus plenior.
What does the word mean, and how is is being used in the context of sensus plenior, Rabbi Eliezer, and the Sephir Yetzirah?
Meaning of the name Notarikon
Notarikon has two primary meanings and applications.
The first meaning is defined by R. Eleiezer in his 32 Rules. These rules no longer exist whole but are discerned by compiling references to them in other writings. 
- Notarikon: Interpretation by dividing a word into two or more parts.
His rule summarizes a practice built on the description of formation of words from breath, to consonants, forming 2-letter gates, and decorating them to form 3-letter roots.  Meaning is given at each level and derived from previous levels.
The second usage describes particular practices used by rabbis and scribes.
NOṬARIḲON (νοταρικόν; Latin, "notaricum," from "notarius" = "a shorthand-writer") 
The second usage describes how rabbis would memorize scripture and scribes would write it in shorthand. When you see studies of letter as acrostics and anagrams, this is the practice being referred to. This is not the usage I [Bob Jones] refer to when discussing the hermeneutic called 'sensus plenior' within SE-BH.
Using notarikon on the word notarikon נוטריקון one derivation is: stretch out נט with the purpose of clarifying נ(ו)ט the revelation ר of creation י through the death and resurrection of the Son of God ק clarifying ו the death of the Son of Man.
Perhaps this is why Eliezer (one of the most quotes rabbis by rabbis) was called a heretic.