Game Mechanics: Target out of view / Blocked buffs should not consume mana (Feb 2001 patch)

[Rygar]

Current Behavior on P99:
When casting a blocked buff:
Cast Breeze on a player that has Clarity already, your Breeze casts and consumes mana and you receive a message:

[Sat Apr 29 20:49:08 2017] Targeted (Player): Noneed
[Sat Apr 29 20:49:08 2017] Stand close to and right click on the Player to consider and inspect her. Use the /toggleinspect command to enable or disable right-click inspecting.
[Sat Apr 29 20:49:14 2017] You begin casting Breeze.
[Sat Apr 29 20:49:16 2017] Your spell did not take hold.

When casting on a target that gets out of line of sight (i'm unsure if this currently consumes mana on P99?):

[Sun Jul 16 00:35:58 2017] You begin casting Anarchy.
[Sun Jul 16 00:36:03 2017] You cannot see your target.
[Sun Jul 16 00:36:03 2017] Your spell is interrupted.

In the 2/21/2001 patch (which had major spell casting revisions) a change took place for the above behavior that was not noted in the patch.

Expected behavior after [Feb 2001] patch:
When casting a buff that is blocked (i.e. did not take hold) it will NOT consume mana and a new message is displayed. From mcoy's Qien logs:

[Sun Nov 11 17:04:03 2001] You begin casting Invisibility.
[Sun Nov 11 17:04:06 2001] Metcalf tells the group, 'Thank you and hello all'
[Sun Nov 11 17:04:07 2001] Fabtiks cheers at Metcalf.
[Sun Nov 11 17:04:08 2001] Your spell would not have taken hold on your target.

With offensive spells where the mob gets out of line of sight or out of range no new message is displayed although mana is still not consumed post Feb 2001, but pre-Feb 2001 mana was still consumed when a spell failed in this manner. Note that per the classic logs no "Your spell is interrupted." message displays:

[Sun Nov 11 14:00:08 2001] You begin casting Ice Comet.
[Sun Nov 11 14:00:10 2001] a festering hag begins to cast a spell.
[Sun Nov 11 14:00:14 2001] You cannot see your target.
[Sun Nov 11 14:00:18 2001] a festering hag begins to cast a spell.

Same thing for if you begin casting yet target gets out of range:

[Thu Nov 15 01:11:23 2001] You begin casting Rend.
[Thu Nov 15 01:11:30 2001] Your target is out of range, get closer!
[Thu Nov 15 01:11:30 2001] Nanelienye tells the guild, 'yes '
[Thu Nov 15 01:11:31 2001] Your feet feel quick.

Evidence:
2/22/2001

Did anyone notice that now if you cast a buff spell on someone
that already has a better buff spell on them it doesn't take effect
AND doesn't use any mana?!
It gets a new message of "Your spell would not have taken hold on your target."
instead of "Your spell did not take hold."

This is a great change! Woot! No more wasted mana on aborted buffs
people that already had it on them. Makes me more likely to toss around
buffs now.

Yep, I noticed that. Very nice, as now I can cast Center on everyone and
if it sticks great, if not, no harm done.

Also, if your target is out of view you no longer waste mana on it. 2
places this would always burn me were solb and Lguk, you'd root
something down and take a few steps back to nuke, but a little corner
would prevent total line of sight, it would say you cant see target
and suck down all the exp. REALLY stunk if you had this happen with
ice comet =)

7/11/2001

Is there a comprehensive list or spreadsheet of stackable spells or non
stackable spells?

I hate it when I get the message your spell would not have taken hold.

I don't know of any list...you just learn them as you go along (at least, I
do). Don't worry, when you see the "would not take hold" message you have
not lost any mana.

I'm sure more evidence can be dug up by request, just let me know.