But to qualify for mailing at the First-Class Mail postcard price, it must be: 1  Rectangular. 2  At least 3-1/2 inches high x 5 inches long x 0.007 inch thick. 3  No more than 4-1/4 inches high x 6 inches long x 0.016 inches thick.
eligible - qualified for or allowed or worthy of being chosen; eligible to run for office; eligible for retirement benefits; an eligible bachelor. qualified - meeting the proper standards and requirements and training for an office or position or task; many qualified applicants for the job.
To be eligible to enter the Academy, a candidate must: 1  Be a citizen of the United States (unless nominated by an official of a country invited by the Department of Defense) 2  Be unmarried with no dependents. 3  Be of good moral character. 4  Be at least 17, but less than 23 years of age by 1 July of the year of entry.