ABSO transaction for adjustment

Hi Experts,

We have 1 asset. Value is 10000 in AA and same in FI. separate document is posted of 1000 in FI. So FI and AA not tallying. To tally FI AA we want to post entry of 1000 in AA and flow in FI and reverse FI entry. So now FI AA tallied.

Now I am trying to use ABSO. Use transaction type 100 for posting. I received an error. 'You cannot post acquisitions to asset'.

Now to avoid this error I used Transaction Type 800. It posted correctly.

1. Now my question is this a right TT I used?

2. Why are we received above error.

3. If I use the TT 800, then we need to tick the revaluation boxes.

Is there any other TT we can use or any other Transaction Code we can use to achieve above requirement?

Regards

Zunaid