Notes can carry on from others.
Notes can carry on from others. A run of notes increments the ID sequentially. 1A and 1B can constitute one long idea together. (They can also represent two separate deeper ideas, expanding on the topic in 1—IDs don’t have to communicate anything beyond where to find a card). This card itself is an example of a continuation—still discussing the ID structure started in 1401,1B.
Finally, interruption 0 is reserved for indexes as they are discovered. 5X29 may have 100 cards under it and as its story emerges, it wants a place toward the beginning to live. Branches 5X29A, 5X30, and 5X29,1 can all be taken in due course, but 5X29,0 waits in the wings to house irregular content.