From Mezu v. Morgan St. Univ., 2010 U.S. Dist. LEXIS 113817 (D. Md. Oct. 22, 2010):

Fed. R. Civ. P. 33(a)(1) provides that "a party may serve on any other party no more than 25 written interrogatories, including all discrete subparts." ***

Probably the best test of whether subsequent questions, within a single interrogatory, are subsumed and related is to examine whether the first question is primary and subsequent questions are secondary to the primary question. . . . Genuine subparts should not be counted as separate interrogatories. However, discrete or separate questions should be counted as separate interrogatories, notwithstanding they . . . may be related.

*** Objections to discovery must be specific, non-boilerplate, and supported by particularized facts where necessary to demonstrate the basis for the objection. *** "[F]ailure to do so may constitute a waiver of grounds not properly raised." ***

It is improper to state, as Defendant did, that production will be made at some unspecified time in the future. See Jayne H. Lee, Inc. v. Flagstaff Indus. Corp., 173 F.R.D. 651, 656 (D. Md. 1997) ("[A] response to a request for production of documents which merely promises to produce the requested documents at some unidentified time in the future, without offering a specific time, place and manner, . . . is treated as a failure to answer or respond."). Therefore, when Defendant stated that the documents would be produced, without indicating when or how they would be made available, Defendant failed to respond to Plaintiff's request for production of documents as required by Fed. R. Civ. P. 34(b)(2)(A). See also Fed. R. Civ. P. 37(a)(4) ("evasive or incomplete . . . response must be treated as a failure to . . . respond"). ***

Additionally, Defendant claimed res judicata as grounds for not responding to document requests. This is a violation of Rule 26(g)(1)(B), which requires that a discovery objection be "consistent with [the Federal Rules] and warranted by existing law or by a nonfrivolous argument for extending, modifying, or reversing existing law, or for establishing new law." Res judicata is an affirmative defense that "may properly be raised through a motion to dismiss under Rule 12(b)(6)." *** It is not a proper ground for objection to discovery. ***

[T]he use of a subpoena to compel Plaintiff to appear for her deposition and to produce documents that already had been requested pursuant to Rule 34 but objected to by Plaintiff was improper in the absence of a Court determination as to whether the disputed documents should be produced.

Courts are divided as to whether Rule 45 subpoenas should be served on parties. Compare Hasbro, Inc. v. Serafino, 168 F.R.D. 99, 100 (D. Mass. 1996) ("discovery of documents from a party . . . is not accomplished pursuant to Rule 45. . . . Rule 34 governs the discovery of documents in the possession or control of the parties") with Mortg. Info. Servs. v. Kitchens, 210 F.R.D. 562, 564-65 (W.D.N.C. 2002) (holding that a Rule 45 subpoena may be served on a party). In either case, a subpoena certainly is not required to depose an adverse party under Fed. R. Civ. P. 30(a)(1). Nor is a subpoena necessary to obligate a party to produce documents, for which a Rule 34 production request suffices. If the parties are unable to resolve a dispute as to the documents to be produced in response to a Rule 34 document production request, the requesting party should address the other party's failure to produce documents through a motion to compel. Fed. R. Civ. P. 37(a)(1). Instead, Defendant attempted to use a subpoena, which is an order of the Court compliance with which if not quashed by the Court, is punishable by contempt, in circumstances where it was completely improper to do so because Plaintiff had objected to producing them under Rule 34, and Defendant had not moved to compel their production. The proper steps would have been first to meet and confer with Plaintiff and, if that proved unsuccessful, to file a motion to compel.