How can we mark people not married just because there is no ceremony?
How can we mark pre most marriages in Scotland as certain uncertain (they could be so much better used -sourced-unsourced or primary source-publication etc etc) when we have no idea if or when they were married by Scottish law--Family search call banns marriages and people mark that certain. Then your committed to have to make a choice certain uncertain---considering the law it then should always be uncertain.
MARRIAGES SCOTLAND history-3 ways of forming a legal marriage without banns or a minister being present.
*A couple were legally married if they declared themselves to be so in front of witnesses, regardless of whether this was followed by a sexual connection. Marriage contracted in this way without witnesses was also legal, but much harder to prove in court unless there was other evidence, such as letters that confirmed what the couple had done.
*A promise of marriage, followed by a sexual relationship, was regarded as a legal marriage - but this had to be backed up by some kind of proof, such as a written promise of marriage, or an oath sworn before witnesses.
*Marriages 'by habit and repute' were also legal if a couple usually presented themselves in public as husband and wife, even if no formal declaration of marriage was made.
Before 1929, Scots law followed Roman law in allowing a girl to marry at twelve years of age and a boy at fourteen, without any requirement for parental consent. However, according to one early 20th-century source*, marriage in Scotland at such young ages was in practice almost unknown.
Runaway marriages to Scotland, particularly Greta Green and other border towns, by young English couples seeking to avoid the need for parental consent for their marriage and to take advantage of the more flexible and informal marriage laws.
ALSO
1855-1919 an illegitimate child’s birth was If the parents subsequently married, the child was legitimised under Scots law provided the parents were free to marry at the time of the birth. ( I have also seen this was the case in Belgium so probably also some other countries)
see
https://www.gla.ac.uk/schools/socialpolitical/research/economicsocialhistory/projects/scottishwayofbirthanddeath/marriage/