I'm running a SQL Server bcp out. When I look at the trace it shows
that the output sproc is being run twice. Between each sproc call
there is 'select BCPCollationName(0x0904D00034,167),
BCPCollationName(0x0904D00034,175)

Does anyone know why the sproc runs twic, or what the BCPCollationName does?

the calling code looks like this:
SET @bcpCmd = 'bcp "exec FNA_VIN.dbo.VCIS_P_SELECT_VIN_FOR_EXPORT '''
+ @FolderName + ''', ''' + @FileName + '''" queryout ' +
@strDestExport + '\' + @FolderName + '\' + @FileName + '.dat' +  ' -c
-T -t'
EXEC	master..xp_cmdshell @bcpCmd

The trace looks like this:
SET FMTONLY ON exec FNA_VIN.dbo.VCIS_P_SELECT_VIN_FOR_EXPORT '1FD3',
'XW46A8' SET FMTONLY OFF
go
exec FNA_VIN.dbo.VCIS_P_SELECT_VIN_FOR_EXPORT '1FD3', 'XW46A8'
go
SELECT BCPCollationName(0x0904D00034, 175), BCPCollationName(0x0904D00034, 167)
go
exec FNA_VIN.dbo.VCIS_P_SELECT_VIN_FOR_EXPORT '1FD3', 'XW46A8'
go
exec sp_unprepare 1
go

Does anyone know what this might be?

The SELECT BCPCollationName(0x0904D00034, 175),
BCPCollationName(0x0904D00034, 167) statement is figuring out which
Collation type to use.

I would assume that it is running the proc twice so that it can
deturmin the column types when creating the BCP output file.