That's not only very dated but not an accurate representation of the reality. The world moves along
https://www.askthe.scottish.police.uk/content/Q56.htm
https://www.gov.scot/policies/landscape-and-outdoor-access/public-access-to-land/
I am aware of the 2003 Act and have been reading thru' it.
The 2003 Act says the access code must be adhered to (and lists the access code conditions)
In 2005 the old 1865 Trespass Act was amended with the addition of 'section 2' which states that if the 2003 Access code conditions are adhered to, then the 1865 Act is not applied. If the Access conditions are not adhered to then the old 1865 Act of trespass is implemented.
Parties lodging in premises or encamping on land, without permission, guilty of an offence.
(1) Every person who lodges in any premises, or occupies or encamps on any land, being private property, without the consent and permission of the owner or legal occupier of such premises or land, and every person who encamps or lights a fire on or near any road or enclosed or cultivated land, or in or near any plantation, without the consent and permission of the owner or legal occupier of such road, land, or plantation shall be guilty of an offence punishable as herein-after provided.
(2) Subsection (1) above does not extend to anything done by a person in the exercise of the access rights created by the Land Reform (Scotland) Act 2003 (asp 2).]