What type of correspondence is appropriate for informal communication between subordinates within the same activity?

The choice of "From-To" memorandum for informal communication between subordinates within the same activity is appropriate because it allows for straightforward and direct communication without the formality of other types of correspondence. This format facilitates clarity and conciseness, making it easier for the intended audience to understand the message quickly.

In organizational contexts, where quick exchanges of information or updates are necessary, the "From-To" memorandum provides an efficient way to document informal discussions or requests. Its informal nature supports ease of communication while still maintaining a level of professionalism. This format is commonly used when the writing is intended to be brief and focused, which aligns well with the needs of subordinates communicating within the same activity.

Other types of correspondence, such as NAVGRAMs and memoranda for formal requests or communications, are more suitable for official communications and may carry additional requirements or structures that are not necessary for everyday interactions between team members. This makes the "From-To" memorandum the ideal choice for informal communication within an activity.