Clocks.fmu: clcoks attribute of the totalInClockTicks variable

In the XML of Clocks.fmu, totalInClockTicks is activated by clocks 1001 and 1003.
  <Int32 name="totalInClockTicks" valueReference="2004" causality="output" clocks="1001 1003"/>

But in the C code, this variable is read and increamented inside activateModelPartition2(). Is this allowed in SE? 
