Usage of TEMP area in classic Step 7

Hello, dear experts.

Could you please clarify this maybe silly question?

I have CPU 414-3 with project in Step 7 V5.5 SP4 HF11.

I have FB with temp vars declaration where last declared word address 12.0

Declaration section size is 14 Byte, 0 Bits from properties dialog

But FB's code is using temp memory like this:

A     "VC010".Service_S.Oper
=     L     15.7

In my understanding code above is using memory beyond declared temp range.

Is it save/acceptable to do so? In languages like C this is very dangerous to use memory like this.

Please advice

Thank you in advance.

@CIONCO,

It seems like these bits were created internally, to represent original language, FBD, which was originally used. Thanks you for clarification