Short answer. Yes. The article on slight physical injuries has a third paragraph that punishes a person who ill-treats another by deed without causing any injury. Injury is what grades the offence, not what creates it, so a slap that leaves no mark is still within the provision.
What the law says
when the offender shall ill-treat another by deed without causing any injury
Revised Penal Code, Article 266 — Slight Physical Injuries. Read the full provision →
What the law says
physical injuries which shall incapacitate the offended party for labor from one (1) days to nine (9) days, or shall require medical attendance during the same period
Revised Penal Code, Article 266 — Slight Physical Injuries. Read the full provision →
The article runs in three descending grades
Art. 266 covers slight physical injuries and maltreatment together, and it separates them by result. The first grade deals with physical injuries which shall incapacitate the offended party for labor from one (1) days to nine (9) days, or shall require medical attendance during the same period. The second covers injuries that neither keep the person from his usual work nor call for medical assistance. The third, the one this question is about, needs no injury at all. Reading only the title of the article is what leads people to assume an unmarked victim has no complaint.
Maltreatment by deed is the paragraph that answers this
The third grade applies when the offender shall ill-treat another by deed without causing any injury. What it requires is an act done upon the person — a slap, a shove, a hand laid on someone in anger — rather than a wound to point at afterwards. The absence of a bruise or a medical certificate does not put the conduct outside the article; it places it in the lowest of the three grades. Words alone, however offensive, are not ill-treatment by deed, and are dealt with elsewhere in the Code if at all.
Why the medical certificate still matters a great deal
The certificate does not decide whether there is an offence, but it very often decides which one. The number of days a person is incapacitated or needs treatment is the dividing line between the grades within this article, and once that period reaches ten days or more the matter leaves Art. 266 altogether and falls under Art. 265 as less serious physical injuries, with heavier consequences. That is why an examination taken promptly, recording what was found and the period of treatment advised, tends to be the single most important document on either side.
What this does not settle
Two cautions belong here. The fines and some other figures throughout the Code were revised by later legislation, so the amounts printed in an old copy are not the current ones and should not be relied on by anybody working out what is at stake. And the same slap can fall under separate special laws where it happens within a family or an intimate relationship, or where a child is involved, with consequences quite different from those of this article. If a complaint has been filed against you, or you are considering one, the classification is the thing to get advice on first.
Related provisions
- Revised Penal Code, Article 265 — Less Serious Physical Injuries
- Revised Penal Code, Article 266 — Slight Physical Injuries