How to change format in all documents at once?

I have a project with numerous pages of text and the text has all different formatting. Is it possible to set the formatting of paragraphs (margins, font, etc.) in all the text pages of a project at once (without having to go to each document one at a time, Select-All, and change format)?

Select the documents you wish to changed and then use Documents > Convert > Convert Formatting to Default Style… That will convert the documents to use the default formatting as defined in the Preferences (or in Project > Text Preferences… if the formatting is overridden there).

All the best,
Keith

Excellent, thanks!! One thing: when I did it, a couple of the documents acquired this in the middle of the text, which I don’t know what it is: a blank line, and on the left and right of the bottom of the line, there are angles like |_ and _| , slightly lighter (gray?) than the normal black text. What do these marks mean?

That sounds as though you are in scrivenings modes - those are indicators to show document boundaries when you have selected single line separators for scrivenings in the Preferences.

Ah yes, thanks - I had multiple items selected and didn’t notice. That’s what it was showing me.