When you submit your work to a creative competition the terms and conditions should make clear which organisations will be granted rights to use your works.
Usually this will be the organiser and sometimes the sponsors, but often competition rules simply say that 'XYZ Company', it's sponsors, subsidiaries, affiliates, and media partners are granted various rights, but the rules do not go on to specify who all the subsidiaries, affiliates, etc, are.
For example, you may have concerns about particular organisations for personal or ethical reasons and you would not wish them to have any rights to use your works.
By not specfying all the organisations who can gain rights to use your works you are being denied the information you need to make a decision.
If you would like to know more about copyright and related rights please read our Guide to Rights and Licensing.