Article 353 of the Revised Penal Code: Definition of libel

In Disini v. Secretary of Justice (2014), the Supreme Court listed them as follows:

1. An allegation of a discreditable act or condition concerning another. For example, saying that someone stole, cheated or has a shameful disease.
2. Publication of the charge. The statement was made known to others.
3. Identity of the person defamed. The person attacked can be identified.
4. Existence of malice. For a private person, the law presumes malice from a defamatory statement (Article 354). Where the offended party is a public official or a public figure, Disini says a stricter standard applies and the prosecution must prove actual malice: that the statement was made knowing it was false or with reckless disregard of whether it was false.

All four must be proven for a conviction.

The article protects "a natural or juridical person". A natural person is a human being. A juridical person is an entity the law treats as a person, such as a corporation or an association. The article also covers statements that tend "to blacken the memory of one who is dead", so the dead are protected too.

Yes. Article 353 was written in 1930, long before the internet. The Cybercrime Prevention Act of 2012 (Republic Act No. 10175, Section 4(c)(4)) punishes libel "as defined in Article 355 of the Revised Penal Code" when it is committed through a computer system. In Disini, the Supreme Court said that this adopts the elements of libel in Article 353 in relation to Article 355, and only adds the computer system to the list of media.

Disini also held that cyber libel is valid against the original author of a post, but void "with respect to others who simply receive the post and react to it". The same post cannot be charged twice, once as libel under the Code and again as cyber libel, because that would violate the rule against double jeopardy. See cyber libel: can you be sued for a Facebook post? and libel vs cyber libel.