. What should be a job application letter’s main points? A job application letter should state the writing purpose clearly, show your best qualification and ask for an interview. It’s better to mention your understanding of the target company and position. 4. What are the requirements on the language used? Brief, concise, emphatic, polite and appropriate etc. 5. Are there any requirement on the length and font? Yes. It is best to limit the job application letter to one typed page.