Northrend Inscription Research may teach you an Inscriber-only glyph. These are not working correctly yet. (El, a warlock, gained Glyph of Resonating Power, which improves a warrior spell she can never learn. And the ability disappeared once logged out.)
The following is known about Inscriber-only glyphs:
* They appear in your Spell Book, as abilities.
* You must be standing near to Lexicon of Power to apply the glyph (pictured right). Lexicon of Power are found near all Inscription trainers.
* Simply click on the glyph in your Spell Book, change the tab to show glyphs, and apply the glyph to a slot as normal.
* No reagents are required for some glyphs, others require materials.
* They can be applied as often as you wish. Like other glyphs, you can only have one unique-named glyph active at a time.
* There is no known way to apply these to other people - only yourself.
((For testing purposes these "inscriber-only" glyphs are being sold by a vendor as normal glyphs, available to anyone. It seems likely that they are intended to discovered as glyphs that anyone can use, and will eventually change to appear as regular recipes and not spells.))