--
  The following sentence on the page 11 requires a little more explanation:  

       Any duration entry without a time unit automatically gets the time unit of 
       the existing duration value in the field.


  Detailed explanation:

       Note that any duration entry without a time unit to the fields Duration and Actual Duration 
       automatically gets the time unit of the existing duration value in these fields, 
       instead of the default time unit set in the <Duration is entered in> box. 

       On the other hand, the Remaining Duration field gets the default time unit in case of entries 
       without a unit, regardless of the time unit of the existing duration value. Following the entry, 
       both the Duration and Actual Duration fields along with the other duration fields automatically 
       get the same unit after the existing values have been converted accordingly.
  
       Example:

       Suppose that the <Duration is entered in> box is set to <Days> (by default), but the time unit of 
       the duration data in the following fields is <Weeks> for a particular task as per user's initial 
       duration entry as weeks:

               (1)
               Duration, Scheduled Duration, Actual Duration, Remaining Duration,
               Total/Free/Start/Finish Slack, Duration Variance
  
               But, at this moment, although it is <Weeks> in the fields above, the following fields 
               display the duration data as <Days> which is the default time unit:

               (2) 
               Baseline Estimated/Baseline Duration, , Start/Finish Variance
               These four fields are sensitive to the <Duration is entered in> setting.

       Now, as soon as you enter a value without a time unit to the Remaining Duration field, all the 
       duration data in the fields (1) will be converted to the values with the default time unit <Days>.

       At this moment, all the fields (1) & (2) will be displaying the duration data with the default 
       time unit <Days>.

       You should immediately Undo and then re-enter the value with the proper time unit, if this happens 
       unintentionally. 

       ------
       No need to mention - if you enter a remaining duration value to an unstarted task, MS Project sets 
       the duration value to the remaining duration value and unit.

       An alternative scenario - just enter a remaining duration value with a different time unit. 
       In this case, again, the conversion to the time unit entered takes place in the fields 
       mentioned. That is, the duration value will be recalculated after the actual duration has been 
       converted accordingly. 

              Duration (new unit) = 
              Actual Duration (converted to the new unit) + Remaining Duration (entered with a different unit)

       You should immediately Undo and then re-enter the value with the proper time unit, if this happens 
       unintentionally. 

       ------

       The Leveling Delay field is initially in elapsed units of the <Duration is entered in> setting for
       the new tasks created. It is not affected by the behaviour mentioned above and the successive changes 
       in the <Duration is entered in> setting for the existing tasks. You may enter values with different units.
       Successive entries without a time unit get the existing time unit.

       -- Author's suggestion: 
       Just be careful while updating the duration data, check the changes in all the associated fields and 
       always include the time units in the entries and be consistent with the units. 
--
       IMPORTANT NOTE:
       The behaviour described above may be different on the version of the product that you are currently
       using. Therefore, you should verify it and beware of it if it works this way on your system too. 
--
       DISCLAIMER:
       It should be noted that any new version of the desktop product released may include some existing features 
       changed, without any public announcement, to function differently than discussed in this eBook. These 
       changes may not be limited to the minor ones. 
--