A model reference letter for an outstanding professor or researcher or individual of extraordinary ability or achievement. This letter may be used by third parties providing references for a foreign worker seeking O-1 (individual of extraordinary ability or achievement) nonimmigrant visa status or lawful permanent resident (LPR) status under the EB-1-1 (individual of extraordinary ability) or EB-1-2 (outstanding professor or researcher) immigrant visa classifications. This Standard Document has integrated notes with important explanations and drafting tips.