(See wikipedia for an initial description of CamelCase)
CamelCase refers to a series of words concatenated into a single word blob (aka no spaces) that is still easily readable because mixed case is used to mark where a new word starts.
lowerCamelCase is a word phrase that is written with a lower case first letter.
Anytime that an acronym is used then the acronym should be consistent case (all upper case or lower case) and the letter following the acronym is the opposite case of the acronym (this covers the case when two acronyms are used in a row, 'rgbXMLtiffImage' is parsed as: RGB, XML, TIFF, Image)
Examples of using lowerCamelCase:
Note that the 'f' in 'getXMLfile' is lower case because of the XML acronym