Long term sick - Holiday accrual query

Hello Community!!

I have a couple of employees on long-term sick accruing holidays. Could someone please explain to me the ACAS terms about carrying over up to 4 weeks?

Does this mean leave is worth 4 weeks ( 20 working days) for a full-time employee?

Long-term sick leave - From Acas

Sick leave is usually considered long-term if it lasts longer than 4 weeks.

If someone has not been able to use their holiday because they've been on long-term sick leave, they can carry it over.

Employees on long-term sick leave can carry over 4 weeks' unused holiday entitlement, unless the employer allows more to be carried over. This holiday must be used within 18 months from the date it's carried over.

Thank you.