I design a quarterly magazine, and each quarter substitute the old content with new content to keep the layout consistent. I'd like to mark the old content so that it's easier for proof readers to spot if I forget to make a subsitution. What is the easiest way to make a universal and conspicuous change to the old content that is also easy to change back when I insert the new content?
Personally, I would create a template of the items always present in the quarterly. Then when the time comes, open the template, save as the date/issue or whatever naming scheme works for you, the add the new content rather than replacing.
This seems to solve the issue you are trying to resolve and, two, it avoids the problems that can come as ID files get recycled. Over time, the recycling can induce issues that can crop up.
Take care, Mike
I produce regular reports that are similar to your magazine in that for the most part the layout - sections, tables, graphs - stays more or less the same. Text changes, tables and graphs get updated, etc. The approach that I take is to have duplicate paragraph styles - one for the current content and one that requires updating. The style that requires updating is identical to the finished style but a different colour, red in my case.
So when I start a new report based on the previous one, I just replace all the relevant paragraph styles with the "update" styles. For example, "Normal" with "Normal Update". Then as I change each piece of content I also change back the paragraph style. Content that still requires updating is then very visible.