A family of Microsoft relational database management systems designed for ease of use.
The colon is more typical in Oracle https://www.quora.com/What-is-bind-variable-in-PL-SQL. I expect this is similar to @dbrDate in SQL server syntax that I am more used to.
I attempted to determine if the colon is viable in MS SQL Server but couldn't quickly find something either way.
I expect this question should be posted in a more appropriate forum.