Additive latency for DRAM READ and WRITE commands

[promach]

In TN-47-10 – DDR2 Posted CAS# Additive Latency Technical Note , what does it exactly mean by Additive latency (AL = 1) is only used for READ commands and will not affect WRITE command timing ?

 

[FvM]

AL=1 seems to be handled specially. However, the same information can't be found in newer Micron DDR2 datasheets, thus I wonder if it applies to all devices.

--- Updated Dec 17, 2021 ---

TN-47-10 isn't available at micron.com, but several other TN-47-xx notes are. Suggests that it has been withdrawn.