🚀 go-pugleaf

I got in the mail yesterday a book I had ordered about 370 assembly programming
I will describe it to the list briefly later, but you will be relieved to hear
that I will be asking fewer naive questions in the future. However, the book,
assuming the user has access to official manuals, omitted to describe three
things having to do with dummy control sections. Not DESECTs. I know what they
are. It failed to describe the Q( ) -type DC or DS operand. It also left out
the DXD and CXD assembler pseudo-codes. I am vaguely aware that they have some-
thing to do with external dummy control sections. Would someone briefly des-
cribe them for me, including the operands they take? Also, would he or she des-
cribe the PUNCH assembler directive? Is it still used on machines without REAL
card punchers?
     On another subject, the computer I use is an IBM 4381-12 running CMS, VM /
SP ver. 4. Does this exclude the possibility that the system has anything to do
with 370 / XA or / ESA?