Unique Key Violation in SQL Server - Is it safe to assume Error 2627?

I need to catch violation of UNIQUE constraints in a special way by a C# application I am developing. Is it safe to assume that Error 2627 will always correspond to a violation of this kind, so that I can use

if (ThisSqlException.Number == 2627)
{
    // Handle unique constraint violation.
}
else
{
    // Handle the remaing errors.
}

?

Solution 1:

2627 is unique constraint (includes primary key), 2601 is unique index

SELECT * FROM sys.messages
WHERE text like '%duplicate%' and text like '%key%' and language_id = 1033

Solution 2:

Here is a handy extension method I wrote to find these:

    public static bool IsUniqueKeyViolation(this SqlException ex)
    {
        return ex.Errors.Cast<SqlError>().Any(e => e.Class == 14 && (e.Number == 2601 || e.Number == 2627 ));
    }

Solution 3:

Within an approximation, yes.

If you search the MS error and events site for SQL Server, error 2627, you should hopefully reach this page¹, which indicates that the message will always concern a duplicate key violation (note which parts are parameterized, and which not):

Violation of %ls constraint '%.*ls'. Cannot insert duplicate key in object '%.*ls'.

¹As @2020-06-18, Database engine errors and events would be the correct page to go to