How does jury duty work? How many are pooled in vs how many get a letter? I got a letter 5 weeks ago for juror duty on 11th September

I'm called for jury duty on Monday 11th, and the phone line says " everyone on jury duty for 11th September must not attend, I repeat you must not attend and phone this number again on Monday 11th AFTER 5pm. Unless a specifically asked to attend, I say again, do not attend.

I'm now scared to go to work in case I'm phoned at work to go in? What does the part mean unless specifically asked?

That means unless you were specifically phoned right? Which I haven't been so that update means don't attend.

I'm guessing this means a case has lasted more than a day or they've used jurors from last week that will be enough to finish Mondays 11th cases.

Also, how do they actually nominate anyone to attend? How many people are asked vs how many people actually get pooled into a case?

I had a plan in place for the whole week regards child care, but that will return to my normal on Monday which is great for Monday but I'm best to just expect Tuesday to mean I'm at court and keep my plans on place?

Thanks