Manual, ch. 6.2 The Two Flavors of Variables, section simply expanded.. controlled leading whitespace, page 63

[DUDZIAK Krzysztof]

bug-make@gnu.org
Edition 0.75, last updated 17 January 2020, of The GNU Make Manual, for GNUmake 
version 4.3, PDF document downloaded
newly from GNU Make web.

Hello,

Reg. example presented at page 63 bottom: when to ignore comment part 
inclusively comment starting '#', I see one whitespace which can be 
seen as leading one: between ':=' and ' $(nullstring)' yet one more whitespace 
between ' $(nullstring)' and '#' opening comment.
Which one is the question of "introducing controlled leading whitespace" about?
Why the whitespace between ' $(nullstring)' and '#' opening comment is to be 
seen as leading space rather than trailing space?

Why is a variable of null-string value used to protect leading space? I 
expected variable of value with
starting leading space (or nothing but one single whitespace in value) to be 
used here.

Actually the elaboration was going to discuss question of introducing 
controlled leading whitespace,
it makes however a switch to discussion of trailing spaces, I miss here 
continuity.
Why one of few edge cases is used to illustrate question of introducing 
controlled leading whitespaces?
Wouldn't be more illustrative and more clear for reader if some non-edge case 
would be used here?
Manual frequently uses edge cases to illustrate concept introduced newly into 
elaborations,
this is not productive for reading and understanding. Please illustrate each 
next make element using
straight forward cases, otherwise description runs onto risk to be unclear if 
effect A is a property
of elaborated element or rather of edge-case, or a mix of those two.

Following statement is also made in ch. 6.2: Leading whitespace characters are 
discarded from your input before substitution of variable
references and function calls. Is this a behavior common for variables of both 
types of expandability, simply and recursive?

Best Regards
kdt