In case anyone doesn't know, this ruling is the result of the For Women Scotland challenge to the Scottish Government on the Gender Representation on Public Boards Act 2018.
Their previous court case ruled that the Scottish Government was wrong to say, in the GRPBA, that the categories of 'woman' and 'man' include everyone who chooses to identify into either of those.
However, the Scottish Government amended the Act to say that the categories of 'woman' and 'man' include those with a GRC as being their chosen sex.
Lady Haldane has now found in their favour.
The GRPBA was intended to increase the proportion of women on public boards.
It seemed to be something that would have very little effect on most people's lives, whether or not self-identified trans people or GRC holders were included in their chosen sex.
Because of this judgement, however, it has become a precedent for all other legislation which refers to one sex or the other.