jargon In general, avoid jargon, the special vocabulary of a particular occupation. Terms that would be unfamiliar to most readers should be avoided or explained.
JPG Acceptable in all references to Joint Photographic Experts Group (also abbreviated as JPEG), one of the most common types of image compression.
junior Third-year undergraduate.
junior, senior, II, III, other name suffixes Abbreviate as Jr. and Sr. and, along with other notations such as II, use only with full names. Do not precede by a comma. Example: John Smith Jr.