Analytics Software

Hi,
Here is "out-of-box" formula from Wrkforce outline member “Regular Employee”
[OpenInputValueBlock]
IF (NOT (@ISUDA([Dimension("DIM_NAME_SCENARIO")], "ACTUAL") ))
IF("Employee Type" == [EmployeeType.FTRegular] AND
"Status" != [Status.Departed] AND
"Status" != [Status.Resigned] AND
"Status" != [Status.TransferOut] AND
"Status" != #MISSING)
"FTE";
ELSEIF("Employee Type" == [EmployeeType.PTRegular] AND
"Status" != [Status.Departed] AND
"Status" != [Status.Resigned] AND
"Status" != [Status.TransferOut] AND
"Status" != #MISSING)
"FTE";
ELSE
#MISSING;
ENDIF
ENDIF
[CloseInputValueBlock]

1) Can someone tell me what is [OpenInputValueBlock]
Is [OpenInputValueBlock] some programming code that is included? If so, where can I find that code? What is the purpose of this code?