QBE file extension is for Saved query
Query By Example dBASE IV - Quattro Pro
Similar to QBE
$D$ - Data
OS/2 Planner
$DB - Temporary file
dBASE IV
$ED - Editor temporary file
MS C
$LN - TLink response file
Borland C++
$O1 - Pipe file
DOS
$VM - Virtual manager temporary file
Windows 3.x
&&& - Temporary file
View all in File Extensions