Term for feature that abstracts RPN program location?

[Orome]

Sorry, I keep getting answers that really aren't addressing the question I mean to ask. But it's my fault for not asking it right.

An example will, I hope, help. Here's some code as it exists in memory on a 42S:

00 { 56-Byte Prgm }
01▸LBL "AAA"
02 1111
03 RTN
04▸LBL A
05 -111
06 END
07▸LBL "BBB"
08 2222 @ This is what CCC does if ENDs are removed
09 RTN
10▸LBL B
11 -222
12 END
13▸LBL "CCC"
14 GTO A @ An error unless ENDs are removed
15 .END.

While this is how the code is actually organized in memory, it's not how it is presented to users. Instead each block defined by LBL <string> ... END is presented at as a separate program, viewed and edited individually, without concern for the others:

00 { 20-Byte Prgm }
01▸LBL "AAA"
02 1111
03 RTN
04▸LBL A
05 -111
06 END

00 { 20-Byte Prgm }
01▸LBL "BBB"
02 222
03 RTN
04▸LBL B
05 -222
06 END

00 { 10-Byte Prgm }
01▸LBL "CCC"
02 GTO A
03 .END.

And when a new program is started with GTO .., it starts empty and on its own

00 { 0-Byte Prgm }
01 .END.

and can be edited without concern for the others

00 { 7-Byte Prgm }
01▸LBL "DDD"
02 .END.

even though in fact it has been added to the end of the others, following an automatically inserted END:

...
11 -222
12 END
13▸LBL "CCC"
14 GTO A
15 END @ This was magically inserted
16▸LBL "DDD"
17 .END.

My question is simply: What is the name for the feature that creates the illusion that programs have no storage-spatial relationship to one another, specifically in the context of moving from say the 34C to the 41 series (e.g., "the 41 series adds ??? which previous HP calculators lacked").

(I'm not asking about the definition of blocks with LBL <string> ... END, nor the local scoping to those blocks of labels of the form LBL <char> or LBL ###, nor about the fact that the all three "programs" are in fact in single linear space, as one discovers if one deletes the ENDs, as noted in the comments.)