Multiple entry 6 months standard visitor visa

Hi
I am hoping you can help me with this.
My parents are applying for a 6 months standard visitor visa. They previously had a multiple entry 6 months std visitor visa last year. With this visa, they visited us only once for the same time and duration as stated on the application and invitation letter.
This time they are planning to visit multiple times, perhaps 3 times, and each not exceeding 2 weeks.
On the invitation letter, i was thinking of the below. Or do you suggest that i should only refer to the first trip in january? I just would like to ensure multiple entry is granted.
“I am writing to confirm that I wish to invite xx xx and xx xx to visit us for about 2 weeks in January 2025 (if the visa is granted in time, between xxth and xxth of January, or at a later date in January), and perhaps a couple of more times after this date -within the visa duration and rules- for special family occasions.”

Any advice is appreciated
Thanks in advance

Hi, i was wondering if any admins have seen my post and would be able to help with my query? Thanks

A visitor visa is always granted as a multiple entry. The UK doesn't issue single visit duration visa like the Schengen states do.

Thanks for your reply.
In this case, shall i just refer to the first trip in the invitation letter or is it ok to keep it as it is as in my first mesaage?
Thanks

Hi, i was wondering if any admins have seen my post and would be able to help with it? Thanks