That is correct. For earnings of at least $10,000 per tax year, an amount of $250 can be accumulated.
I'll give you an example. Let's say that four years from now, I intend to take a course to improve my skills that will cost $2,000. While I am working, I accumulate $250 per year. After four years, I would have accumulated $1,000. I could receive a refund of up to 50% of my course fees.
For a $2,000 course, I could receive a reimbursement of $1,000. If I decided that the time was not right to take the course, I would continue working. For every year, I would accumulate a certain amount for training fees until I took the course.