(1) A person is guilty of an offence if, with intent to cause a person harassment, alarm or distress, he—
(a) uses threatening, abusive or insulting words or behaviour, or disorderly behaviour, or
(b) displays any writing, sign or other visible representation which is threatening, abusive or insulting,
thereby causing that or another person harassment, alarm or distress.
(2) An offence under this section may be committed in a public or a private place, except that no offence is committed where the words or behaviour are used, or the writing, sign or other visible representation is displayed, by a person inside a dwelling and the person who is harassed, alarmed or distressed is also inside that or another dwelling.
(3) It is a defence for the accused to prove—
(a) that he was inside a dwelling and had no reason to believe that the words or behaviour used, or the writing, sign or other visible representation displayed, would be heard or seen by a person outside that or any other dwelling, or
(b) that his conduct was reasonable.
(4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(5) A person guilty of an offence under this section is liable on summary conviction to imprisonment for a term not exceeding 6 months or a fine not exceeding level 5 on the standard scale or both.