If you are using the Internet and Web resources for a business publication, under which conditions is it not necessary to include a citation?

I can't think of any! All of us need to ALWAYS give credit to other people for their ideas and words.

You don't always have to do parenthetical citation or footnotes, though, especially if it's a rather short piece, such as a letter or memo. As long as you give the author and source information in your sentence (perhaps as an introductory clause or phrase), it would be fine.

http://www.bu.edu/library/guides/pml/citation.html
Read carefully.

When using Internet and web resources for a business publication, it is typically necessary to include citations to acknowledge the sources of information and to avoid plagiarism. However, there are a few conditions where it may not be necessary to include a citation:

1. Common knowledge: If the information you are using is widely known and considered common knowledge, you do not need to provide a citation. Common knowledge includes information that can be found in multiple reliable sources and is known by the general public, such as historical events or well-established facts.

2. Original research or personal experiences: If you are sharing your own original research findings or personal experiences, it is not necessary to include a citation since you are the source of the information. However, it is often helpful to provide some context or background to establish your authority or expertise in the subject matter.

3. In-house data or proprietary information: If you are using data or information that is specific to your own business or organization and not available to the public, you do not need to cite the source. However, you should clearly state that the information is based on internal data or proprietary information to maintain transparency.

4. Public domain sources: Some materials, such as government reports or documents, are readily available in the public domain and can be used without the need for a citation. However, it is still best practice to provide a reference to the original source for readers to access if they wish.

In general, it is important to exercise judgment when deciding whether or not to include a citation. When in doubt, it is always safer to err on the side of caution and provide a citation to give credit to the original sources and avoid any potential issues of plagiarism. Remember, citations also add credibility and allow readers to verify the information provided.