Zakirai v. Muhammad  17 NWLR (Pt. 1594) 181 at 230-231, paras. G-D, per Augie, JSC:
“His [The Appellant’s] objection was a complaint against the competence of the trial court to entertain the suit because the originating summons was not endorsed or marked as required by the said Act and Rules, which touches on the procedural rules that got parties to the court, and nothing whatsoever on the facts that led to the cause of action or substance of the suit filed by the first respondent. Any defect amounted to a mere irregularity that can be waived by the parties… In this case, the Appellant entered a conditional appearance and also filed a counter-affidavit [to the Originating Summons], which means he waived the irregularity that he complained of, and had submitted to the jurisdiction of the court.”
The Court reasoned that while substantive jurisdiction of the court cannot be waived, a party can waive an issue relating to procedural jurisdiction of the court. In effect, the Court was of the view that the issue relating to the endorsement and marking of an originating process for service outside jurisdiction as provided for by the Sheriffs and Civil Process Act is an issue touching on the procedural jurisdiction of the court and thus can be waived.
The above position appears to run contrary to the Supreme Court position in the case of Owners of MV “Arabella” v. N.A.I.C.  11 NWLR (Pt. 1097) 182 where the Court held that such irregularity is not a mere one that can be waived and that it is immaterial that the defendant had taken steps. It was held there that failure to comply with the Act is fatal as it robs the court of jurisdiction to determine the suit.
No doubt, Owners of MV “Arabella” v. N.A.I.C. attempted to settle the issue which was hitherto shrouded in controversy given earlier seemingly conflicting decisions of the Supreme Court on the point. Just when it looked like the issue is now settled, the Supreme Court in the instant case of Zakirai v. Muhammad now appears to “unsettle” the situation. In fact, without expressly confirming the holding of the Court of Appeal on the point, it appears that what the Court of Appeal said on the issue is compelling. At pages 218-219, the Supreme Court in Zakirai (panel of 5) referred to the Court below which had observed that the decision in “Arabella” was handed down by a panel of 5 Justices of the Supreme Court and so cannot override the earlier position of the apex Court taken by 7 Justices of the Court (full court) in Odu’a Inv. Co. Ltd. v. Talabi  10 NWLR (Pt. 523) 1 to the effect that non-compliance with the provisions of section 97 of the Sheriffs and Civil Process Act is an irregularity which only renders the writ voidable, not void, and that such unendorsed/unmarked writ as stipulated by the Act can be voided at the instance of a defendant who acts timeously and without taking further steps in the matter.
Nevertheless, it is perhaps safe to conclude that being a later decision, Zakirai v. Muhammad has superseded Owners of MV “Arabella” v. N.A.I.C on this issue. It is our view that any decision that reduces the effect of technicality is totally welcome.
The Supreme Court further seised the opportunity to reiterate the position that in a suit involving more than one defendant (within and outside jurisdiction), it does not lie in the mouth of the defendant within jurisdiction (the Appellant in this case) to complain about procedural irregularity in service on a party outside jurisdiction (the 2nd and 3rd Respondents). Augie, JSC remarked: “in this case, the Appellant is not a Knight in shining armour, and the second and third respondents did not need him to fight their battles.” See page 232 of the report.