What does the editorial mark IC mean?

That is probably "lc". Check this list of editorial marks.

http://www.colorado.edu/Publications/styleguide/symbols.html

Ok, thanks

To understand what the editorial mark "IC" means, you can follow these steps:

1. Research editorial marks: Editorial marks are symbols or notations used by editors to indicate specific changes or suggestions on a written document.

2. Consult a comprehensive list: There are numerous editorial mark lists available online that provide explanations for each symbol used by editors. Look for a reliable source that includes a wide range of editorial marks.

3. Find the "IC" mark: Once you have a list, search for the specific editorial mark "IC." Scan through the list alphabetically or use the search function if available.

4. Understand the meaning: Look for the explanation or definition provided for the "IC" mark in the chosen source. It may vary slightly depending on the source, but typically, "IC" stands for "I don't understand" or "intelligibility concern." Editors use this mark to indicate that they find a particular word, phrase, or sentence difficult to comprehend or that it is unclear in its intended meaning.

It's worth noting that while "IC" is a common interpretation of this mark, different editing styles or individuals might attribute different meanings to certain symbols. Therefore, always confirm the symbol's meaning within the specific context of your document or consult the editor who used it for clarification.