ELCAS are the Enhanced Learning Credits Administration Services. The Ministry of Defence brought in this scheme with the aim to help resettle ex-forces members into a new career. To do this, they are helping to fund their career education courses after or during their service in the military. When enlisting in the forces you will be asked whether you want to opt into the ELC scheme. However, you may be eligible to apply for ELC even after retiring from service.
https://www.theccm.co.uk/elcas/