Informal application: The five most important tips for cover letters and CVs. The main focus of an informal application is its brevity.
If you're unlucky, your application will be rejected from the start if it's too long. You should try to keep both the cover letter and resume to one page. The leaner applications are a means of saving time on the company side and making a quick pre-selection. The remaining candidates are then expected to submit more detailed applications or go straight to a personal interview.