SharePoint: Multiple default values using “Column default value settings”

Problem

SharePoint doesn’t allow selecting multiple default values in “Column default value settings” of a list, even though the column in question is choice and allowing multiselect.

Solution

Using browser, you cannot do it, but modifying /yourlist/forms/client_LocationBasedDefaults.html using SharePoint Designer or programmatically makes it possible. Just use format ;#CHOICE1;#CHOICE2;#, e.g.,
<DefaultValue FieldName="MyMultiChoiceFieldName">;#Valintatalo;#Citymarket;#</DefaultValue>