<S-Arrows> weird behavior (<S-UP>,<S-DOWN>,<S-LEFT>,<S-RIGHT>)

Question

<S-DOWN>

Moves the cursor back a few characters. But not always by the same amount.

<S-UP>

Moves the cursor to the end of the line.

<S-LEFT>

Deletes the next two lines.

<S-RIGHT>

Deletes the next two lines, adds empty line, enters insert mode at said empty line.

This happens in any mode, visual, insert and normal mode.

Looking at h:index, it says noting about this behavior. If I enter

unmap <S-LEFT>

or any other mentioned command, I am prompted with the "no mapping" message.

Any idea what is happening, and how to prevent it?

EDIT

I also tried adding

map ^[[1;2B <Nop>

where ^[[1;2B is the result of pressing Ctrl+v . But than, upon pressing I am prompted with

E486: Pattern not found:

Also note that after adding such mapping for all the combinations, the

<S-UP>
<S-LEFT>

work, meaning, they do nothing. But for

<S-DOWN>
<S-LEFT>

I am prompted with the message

E486: Pattern not found:

Answer 1

As I have found the solution in the mean time, I will post it here.

One should set for vim what the correct escape keys are. In my sitution, this means that I had to add

set <S-UP>=[1;2A
set <S-DOWN>=[1;2B
set <S-LEFT>=[1;2D
set <S-RIGHT>=[1;2C

into the .vimrc. The rhs is generated by pressing Ctrl+v+. Now the sequences behave as specified in the h:index.