All the tag is for is the model and ratio.
231...style type of t-case
272... is the internal ratio.
There is probally 20 or so versions of a NP231 t-case. They are used in Jeep chevy and dodges. but the housings and input/outputs are different.
The cherokee's tail shaft is slightly different from your TJ's. But CAN still be used with a little know how and modding.
The spline count can be different and many cherokees have a 21 spline count.
Your NP231j in your 99 wrangler with a AX-15,5speed has a 23 spline input shaft.
Check the cherokees spline count. if 21..no go...but you can use the front housing. If 23spline...yes but you will have to do a little modding to get the rear tail shaft to fit the driveshaft.