So, through the years, I have an on and off user of TeX. Although I have master some things in the past, I find myself to re-read books at the Introductory level. Recently, I have started reading Marc van Dongen's "LaTeX and Friends" introductory book. This was published in 2012 I presume.
Now, as I progressed in my reading, I have found that some of the commands in the text are not recognized by my LaTeX Distribution: I am using texlive on a Windows 10 64-bit Laptop and writing with Texmaker as the editor.
For instance, here is a screenshot:

As you can see the command \endashabove was not recognized and I got an error. After much googling, I found that \textendashis the working alternative. This is a code snippet from a book that was published 12 years ago yet my LaTeX distribution cannot typeset the code from it. I have tried to look at Esenbach and Trettin's l2tabu which sums up a list of deprecated commands and packages and suggests the newer versions. Unfortunately, I haven't found anything related to the \endash command.
Now I am wondering if there is a list of obsolete commands that I should be aware of (other than l2tabu obviously).
\newcommand{\endash}{--}, or included another package that defined it. – Werner Oct 28 '21 at 18:52