thanks to the help of @sylumer, I can now preview and print using yellow highlight for pre code, which according to markdown syntax is backtick delimited.
I serendipitously discovered by accidentally pressing on the tab key that if I press on the tab key:
1- at the beginning of a sentence
2- if the sentence starts at the left margin
The sentence converts to pre code display. The font changes, with a yellow highlight, just as happens using backticks.
I was wondering why this is
I don’t see any mention of tabs in markdown / CSS syntax, except for code, which is something else.