Can anyone help me with this target report? Y1

[minimaxkids]

We have had an appalling communication from school regarding individual child English targets.
It is utter gobbledegook to us.
It states DD targets are;

I usually spell high frequency words correctly (A13)
I am working towards making sentences by joining simple clauses together (A2)
I usually use full stops and capital letters correctly (B5)

What do the numbers mean? These are obviously statements from something. Can anyone help me understand it?

I'm a year 1 teacher and I don't know what the number/letter combos allude to.

But:

High frequency words = there's a list, 100 first ones. Common words that they'll be using in their reading and writing a lot. Lots of lists online if you google it.

Joining simple clauses together eg: "There is a tree. It has green leaves." would change to "There is a tree and it has green leaves."

Full stops and capital letters pretty self explanatory.

Those are all standard things for year 1 to be working towards. I imagine that the teacher has gotten them from whatever form of assessment they use at your child's school.