The EXCOS of the school association in question, the P.R.O especially, has the responsibility of making sure everyone learns about the day, time and venue for a congress meeting and that everyone attends. In light of this, they must use every communication channel possible to get this across to all the members.
Generally, the common means of communication used to get this across is through notice boards and other strategic areas within the school premises or the departmental or faculty building as the case may be. While this is undoubtedly effective to an extent, it has it limitations, as not everyone gets to hear about this.
A very effective communication tool that can get important meeting reminders straight into the ears of everyone involve is bulk SMS. Once you have the phone numbers of all the members of the association, all you have to do when congress meetings are coming up is go your bulk SMS account and send them a meeting reminder SMS. With this, there are no excuses for absenteeism, and voluntary defaulters can then be punished accordingly.
Registration of an SMS account on SmartSMSSolutions is free. Also get free SMS units instantly.
To offer much though in such meetings, the EXCOS must be prepared. See here how to get better prepared for meetings as EXCOS.