MLI means Model List Item.
ML (Model List) is a "short" version of MLI.
Some previous definitions of ML (which is short for MLI) are in these threads:
If you need more help after reading these threads, write back with a more specific question.
"MLI" stands for Model List Item.
The Model List is a top level list of the major drawings for a GE gas turbine. Each drawing is a different Item number. For example, Item 0414 is always the Piping Schematic Device Summary drawing. Some of these drawings are internal and some are provided to the customer. The Model List itself is an internal document.