I like your "Mini Tutorials" and maybe Andrew like to consider a special Rubric in this Forum to share something like that in only one Place . Sort of "User to User".
How ever - in this case I like to consider that this tutorial should be called "How I create a Library Item" and not just a Block.
A normal Block belongs only to the particular drawing. The goal is to us it only in this drawing or maybe in a limited form to use it via Paste© in other opened drawings.
A library Item is considered to be used in many Drawings for Standardization or just to do the work once for a recurring (boring) task. (Who likes really to draw every day 30 times a Hex Bolt 6x40 just because he need it every day 30 times ....
My recommendation regarding to clives explanation is to draw the considered Library Item (Maybe a Hex Bolt 6x40
) in an empty Drawing.
Align it to the the absolute zero point what will later be your reference point.
Don't make a block out of it - that is something what QCad will do for you and an additional block brings only a confusing (for you and QCad) nesting.
Store it in the Library Folder with a meaningful Name. This name (except the suffix .dxf) will later appear in the Drawing Block List of your drawing when you use the Library Item.
Be carefully with the name - if you use this Library Item in a drawing witch has already a block with the same name - QCad will ignore the Library Idem and will use the existing Block.
Clive - please compare my experience with your Tutorial and if you agree full or partly with my way feel free to implement important variations in your Tutorial.
I'm sure - this Forum and your work colleagues will appreciate your good support.