So - I think keeping track of what books the library has and especially what tractatus you've read and who uses what in which season is a chore that doesn't really add to the "Mythic" aspect of the game. So I'm toying with the idea of creating a more rules-light and Mythicky version of the rules. Comments or other suggestions welcome!
The basic idea is to get rid of tractatus, leaving us only with summa. But, we need variety, and I don't want to make building a good library so easy as to write a summa. So....
Building a Library: Each section (Ability/Art) of a library is built up with experience points, so the library has a Level in it. A contributer writing to it adds 1 xp per season, assuming that his Level is at least twice the library's level in the topic. The quality is typically 10 (but see below).
It is possible to copy a library section. A skilled scribe can do it at 3 xp per season. You can only add xp from one library to another to the extent that the specific content they hold doesn't overlap; the storyguide decides how much can be copied, but usually only little knowledge can be copied from a lower Level library section, since the knowledge within it is largely already included in the higher Level section.
Each library can also have certain Qualities. A library can have any number of Qualities, and can have the same Quality several times (but usually for different sections or so on; there is no use to having the identical same Quality twice!).
High Quality: A certain section of the library is of higher-than-normal quality, to some Level. High quality sections are created by Good Teachers (adding +3 to Quality) and/or contributers with +3 or higher Communication (adding +3 to the Quality); a high quality section can thus reach Quality 16. A writer with Mythic Communication can even add another +3, but this is virtually unheard of. Often the prized writers cannot write to the full Level of the library, so both the high quality and standard quality sections are retained.
Poor Quality: A certain section of the library is of a lower-than-normal quality. This is usually caused by being composed virtually only of contributers of low (-3 or lower) Communication, but can be also due to damage to the library or other reasons. If the poor quality is caused by poor Communication contributions, this can be overcome by balancing it with contributers of higher Communication (the amount needed depends on storyguide fiat); a standard library contains contributions of low Communication, but they are balanced out by even a few writers with higher Communication. It is very rare for a library to have a a high-Level poor quality section, and poor quality sections are largely limited to spring covenants.
Realia: The library includes objects and displays that assist in acquiring practical knowledge in one section. For this topic, increase the Quality by +1, up to the Realia's Level. Realia levels are again built with experience points, just like the section is, but amassing them requires actually collecting and preparing the displays, which may be limited by availability (i.e. obtaining the materials may require an adventure).
Significanto: The library includes a unique artifact that can serve as a focus of study in one Section. Examples might include a book on Ignem fashioned from the scales of a great dragon, or insights into Mentem gained by examining the box that once given to Pandora. Treat this as studying from a certain number of pawns of raw vis (determined by the storyguide). Significanto typically form inadvertently by powerful magic or, rarely, are given to mortals by powerful spirits, although sometimes they can be unique enriched items (such the above-mentioned book).
Unorthodox Media: Some sections of the library are provided by an unorthodox medium, such as ghosts trapped in mirrors or changing glowing glyphs upon obelisks. Book Learners don't get the usual +3 bonus for these sections, but characters with other Virtues or Flaws might. Adding content to an unorthodox section may require special magic or techniques.
Grimoire: The library contains a grimoire, detailing the True Names of some locale or similar narrow focus. A character may learn two True Names per season of study; each Grimoire contains only a limited number of True Names, of spirits that are determined by the storyguide. The character also earns 2 experience points in the appropriate (Realm) Lore, limited by the section's Level. Learning True Names not through Grimoires can generally only be done with adventure XP, although knowledge of certain True Names can be granted by some powerful spirits. A person can write a grimoire about the true names he knows as a seasonal activity, and many grimoires are known by the name of their author ("Allasiter's Grimoire", and so on).
Corrupted: A section of the library has been corrupted by infernal machinations, subverting its contents towards evil. Corrupted knowledge applies a -3 or +3 modifier when it is applied, depending on whether its application serves or hinders the Infernal. It furthermore adds three botch dice, and their effects tend to further the Infernal too. Characters aligned with the Infernal effectively always receive the bonus. A corrupt section can be identified only by someone versed in the field (of a Level at least equal to the Level of the library), and even then requires a successful (Perception + Infernal Lore) check. The ease factor depends on the manner of the corruption, which generally requires the insertion of corrupting texts into the section.
Certain angels are famous for being able to detect corrupted knowledge, and its use can sometimes be detected by characters with the Sense Holiness and Unholiness supernatural ability.
Extensive: A section of the library is extensive, providing a greater chance to find specific information sought. Add +3 to Research attempts in this section. Research allows a character to use the library's Level instead of her own score in answering a particular question within the topic. It takes hours, days, or even an entire Season, depending on how thorny and specific the question is (as decided by the storyguide). Roll (Intelligence + Level) against an Ease Factor set by the SG to see how fruitful the research was, once it is concluded. Answering roughly how long and how hard the research will be is an easy (EF 6) task taking but a few hours of research or a moment's contemplation by somone with a score in the field.
Specialty: A certain section is particularly effective in a certain sub-field, a specialty of the Ability. Characters gaining experience from it may change their specialty to fit it, and Research within this narrow topic is at +1.
This quality cannot be applied to an Art.