Phasing scrolls

[Jymamon]

I'd heard mention a few times that a scroll can be checked for being fresh by attempting to phase it. Deciding to finally seperate out my new/used scrolls, I looped through the bunch I had lying around. Along the way, I noticed something I didn't expect- some unlocked scrolls would phase, but others would not.

For example, this scroll will phase:

You wave your stone at a moon-stamped faded blue paper.
As the stone passes over the scroll, you sense:
(609) Sun Burst with many charges remaining.
(114) UnPoison with a number of charges remaining and the potential to add many charges.
(613) Self Control with a number of charges remaining and the potential to add a number of charges.
(119) Spirit Dispel with a number of charges remaining.
Cast Roundtime 3 Seconds.
s>prep 704
You begin drawing a faint, twisting symbol while softly intoning the words for Phase...
Your spell is ready.
s>cast my paper
You gesture at a moon-stamped faded blue paper.
The paper becomes somewhat insubstantial and appears lighter.


But this one won't:

You wave your stone at a moon-stamped faded blue vellum.
As the stone passes over the scroll, you sense:
(109) Dispel Invisibility with a number of charges remaining.
(612) Breeze with a number of charges remaining.
(609) Sun Burst with a few charges remaining.
(603) Foraging with no charges remaining and the potential to add a few charges.
Cast Roundtime 3 Seconds.

s>prep 704
You begin drawing a faint, twisting symbol while softly intoning the words for Phase...
Your spell is ready.
s>cast my vel
You gesture at a moon-stamped faded blue vellum.
A moon-stamped faded blue vellum resists the effects of your magic!


Am I mis-reading the meaning of detecting the status of the scroll? Assuming not, is there anything meaningful between the ones that will/won't phase or is it just randomness?

[Murkshev]

What makes these two scrolls different? Find that variable and then retest. Find another scroll that is both unlocked. One that has charges on the scroll still that are unlocked. The other that has a unlocked but out of charges on it. If those two new scrolls act in the same manor, you have your deduction.

[Fallen]

If a scroll won't phase, then it should act like it is locked. Scrolls that you have already infused, it can lock as you use it as it runs out of mana. Try re-infusing that one.

[Murkshev]

You begin drawing a faint, twisting symbol while softly intoning the words for Phase...
Your spell is ready.
>
You gesture at a silvery palimpsest.
A silvery palimpsest resists the effects of your magic!
Cast Roundtime 3 Seconds.
>
You wave your stone at a silvery palimpsest.
As the stone passes over the scroll, you sense:
(308) Well of Life with a number of charges remaining and the potential to add no charges.
(319) Divine Wrath with many charges remaining.
(207) Purify Air with a number of charges remaining and the potential to add no charges.
(303) Prayer of Protection with a number of charges remaining and the potential to add no charges.
Cast Roundtime 3 Seconds.

Okay so this is an infused and used palimpsest. Perhaps the blue paper in the first post is only unlocked and not infused. And this is would still phase cause its considered fresh still? While the blue vellum is unlocked, and infused and perhaps has been used. That makes sense.