Final answer:
In client files, underlined or highlighted portions of legal documents are not required as they are not underlying legal authority. Case briefs, relevant regulations, rulings, and a compendium of legal citations that demonstrate research and analysis are essential to include.
Step-by-step explanation:
In the context of what should be included in a client's legal file, a practitioner should include virtually all pertinent legal documentation and analysis to provide comprehensive support for the client's case. However, the inclusion of underlined or highlighted portions of important legal documents is not a type of underlying legal authority and thus should not necessarily be included. The key components that should be included are case, regulation, and ruling briefs that are relevant to the client's situation, as well as a listing of legal citations and computer files that evidence the researcher’s analysis. These elements are crucial in backing up claims with precedent and legal authority, ultimately assisting in persuading the court to agree with the argument presented.