Always try to write from the perspective of the reader. What is obvious to you will not necessarily be obvious to everyone reading your publication or correspondence. When in doubt, it is better to err on the side of too much information. Always use the full official names of offices, departments, programs, and committees in your first reference. In subsequent references it is generally not necessary, and can be tedious, to repeat the complete name.
All communication is persuasion.
You are writing to an individual or to a group with the goal of altering their behavior or attitudes. You want them to attend an event, or to make a contribution, or to be more favorably disposed toward a particular action. Try to understand where your readers are now and guide them from where they are to where you want them to be. Those things that will motivate a group of alumni may not necessarily motivate a group of prospective students. The two probably have different values, different levels of interest, and different experiences and knowledge.