As a detective, the first thing I always do when solving a crossword puzzle clue, is to read it thoroughly to understand what it’s asking me. In this particular clue ‘Passport Requirement‘, I knew my answer had to be a document or item that is necessary for a passport. I considered a few options, such as ‘signature‘ or ‘proof of citizenship,’ but they did not fit the number of letters. However, the word ‘requirement‘ stood out, hinting that the answer had to be an essential element for one’s passport application, and at that moment, it hit me that a photo would be the perfect answer! A photo is a critical requirement needed for a passport, as it serves as a form of identification for the passport holder. It was an ‘Aha!‘ moment, and in a few seconds, I penned down my answer, confident it would be the right one. In conclusion, my deductive reasoning and knowledge of what is required for a passport application led me to the correct answer of ‘PHOTO‘ for the cryptic crossword clue of ‘Passport Requirement‘.