Issues the Court of Appeals can rule on
As an exception, the CA may review errors that are not assigned but are closely related to or dependent on an assigned error.

As an exception, the CA may review errors that are not assigned but are closely related to or dependent on an assigned error.

Here is something to do with procedure. In a petition for declaration of marriage, one spouse raised an issue on appeal with the Supreme Court (SC). The party alleged that the Court of Appeals (CA) gravely abused its discretion in dwelling on and ruling on an issue that was not brought up by the other party.
Under the rules of procedure, this party espoused, only matters raised on appeal must be discussed and ruled upon by the appellate court. Ergo, going beyond those issues becomes a grave abuse of discretion. Is the petitioner correct?
Here is how the Supreme Court decided that particular issue.
“Generally, only matters assigned as errors in the appeal may be resolved by the CA. As an exception, the CA may review errors that are not assigned but are closely related to or dependent on an assigned error.
“Rule 51, Section 8 of the Rules of Court, as amended, provides: Rule 51: Judgment. Sec. 8. Questions that may be decided. No error which does not affect the jurisdiction over the subject matter or the validity of the judgment appealed from or the proceedings therein will be considered unless stated in the assignment of errors, or closely related to or dependent on an assigned error and properly argued in the brief, save as the court may pass upon plain errors and clerical errors.
“In Catholic Bishop of Balanga v. CA, this Court enumerated the exceptions where the CA may review errors that are not assigned before it, thus: True, the appealing party is legally required to indicate in his brief an assignment of errors, and only those assigned shall be considered by the appellate court in deciding the case.
“However, equally settled in jurisprudence is the exception to this general rule. Roscoe Pound states that ‘according to Ulpian in Justinian’s Digest, appeals are necessary to correct the unfairness or unskillfulness of those who judge.’ Pound comments that ‘the purpose of review is prevention quite as much as correction of mistakes. The possibility of review by another tribunal, especially a bench of judges [. . .] is an important check upon tribunals of first instance. It is a preventive of unfairness. It is also a stimulus to care and thoroughness, so as not to make mistakes.’
“Pound adds that ‘review involves matters of concern both to the parties to the case and to the public[.] It is of public concern that full justice be done to [e]very one.’ This judicial injunction would best be fulfilled and the interest of full justice would best be served if it should be maintained that [. . .] appeal brings before the reviewing court the totality of the controversy resolved in the questioned judgment and order apart from the fact that such full-scale review by appeal is expressly granted as a matter of right and therefore of due process by the Rules of Court.
“Guided by the foregoing precepts, we have ruled in a number of cases that the appellate court is accorded a broad discretionary power to waive the lack of proper assignment of errors and to consider errors not assigned. It is clothed with ample authority to review rulings even if they are not assigned as errors in the appeal.
“Inasmuch as the Court of Appeals may consider grounds other than those touched upon in the decision of the trial court and uphold the same on the basis of such other grounds, the Court of Appeals may, with no less authority, reverse the decision of the trial court on the basis of grounds other than those raised as errors on appeal.
“We have applied this rule, as a matter of exception, in the following instances: (1) Grounds not assigned as errors but affecting jurisdiction over the subject matter; (2) Matters not assigned as errors on appeal but are evidently plain or clerical errors within contemplation of law; (3) Matters not assigned as errors on appeal but consideration of which is necessary in arriving at a just decision and complete resolution of the case or to serve the interest of justice or to avoid dispensing piecemeal justice;
“(4) Matters not specifically assigned as errors on appeal but raised in the trial court and are matters of record having some bearing on the issue submitted which the parties failed to reuse or which the lower court ignored; (5) Matters not assigned as errors on appeal but closely related to an error assigned; and (6) Matters not assigned as errors on appeal but upon which the determination of a question properly assigned, is dependent.
“Thus, the CA has the discretion to consider the issue and address the matter where its ruling is necessary: (a) to arrive at a just and complete resolution of the case; (b) to serve the interest of justice; or (c) to avoid dispensing piecemeal justice. This is consistent with its authority to review the totality of the controversy brought on appeal.
“From the foregoing, the CA is allowed to resolve matters not assigned as errors if it finds that their consideration is necessary in arriving at a complete and just resolution of the case. As mentioned above, the CA may review errors that are not assigned but are closely related to or dependent on an assigned error. This exception lies in this case.”
The facts and quoted portion of the decision are from SC G.R. 265808 (22 January 2025).