But it's not common law any more, Breach of the Peace in Scotland was replaced four years ago:
Criminal Justice and Licensing (Scotland) Act 2010
38 Threatening or abusive behaviour
(1)A person commits an offence if
(a)A behaves in a threatening or abusive manner,
(b)the behaviour would be likely to cause a reasonable person to suffer fear or alarm, and
©A intends by the behaviour to cause fear or alarm or is reckless as to whether the behaviour would cause fear or alarm.
(2)It is a defence for a person charged with an offence under subsection (1) to show that the behaviour was, in the particular circumstances, reasonable.
(3)Subsection (1) applies to
(a)behaviour of any kind including, in particular, things said or otherwise communicated as well as things done, and
(b)behaviour consisting of
(i)a single act, or
(ii)a course of conduct.
(4)A person guilty of an offence under subsection (1) is liable
(a)on conviction on indictment, to imprisonment for a term not exceeding 5 years, or to a fine, or to both, or
(b)on summary conviction, to imprisonment for a term not exceeding 12 months, or to a fine not exceeding the statutory maximum, or to both.