Dear Khaled,
Long Long ago on an RFC far far away, ISON helped establish a means for users to be notified when their friends come and go from IRC. It has been an essential feature on so many clients and has kept people in touch for years.
However, the ISON command itself is rather deprecated, as it has limited functionality and consumes unnecessary network resources.
Most of the mainstream IRC Networks and Daemons support the MONITOR command, which is far superior to ISON as it provides for immediate updates to the client and only requires one-time-use instead of polling the server every 30 seconds.
Those networks that don't support MONITOR, may prefer WATCH instead, although WATCH has become deprecated in its own right it is still a superior alternative to ISON with the same client and network benefits.
Since mIRC is still the mainstream IRC client among Windows users, and with some Linux/Mac users (via emulation), the network resources that it uses does matter. The ISON commands may be small, but they are frequent, and its elimination could save gigabytes of network traffic over the large scale. This would be especially well received by small IRC servers with limited resources.
I would like to see it made a preference, at least.
I would also like to see that MONITOR, WATCH and ISON replies can be used within scripts. At present, it is not possible to hook ISON replies with the RAW prefix. I hope that MONITOR and WATCH would not be restricted from scripts as well.
