until this economy gets sorted out.

I think these are the relevant bits.

Paragraph 1:

(1) Split doubleheaders shall not be scheduled in the original schedule. Provided that neither of the Clubs involved in the proposed rescheduled game already has played or has been rescheduled to play a total of two split doubleheaders in that championship season:

(a) each Club shall have the right to reschedule any postponed game as a split doubleheader when ticket sales for the game at the time of postponement exceed, in any respect, the number of comparable tickets available to be exchanged by the Club for the balance of the championship season, and both the postponed and rescheduled game occur in the last regularly scheduled series between the two Clubs at the Club’s park; and
(b) when there is no practical alternative to doing so, the Boston Red Sox and Chicago Cubs shall have the right to reschedule a postponed game as a split doubleheader to be played in, respectively, Fenway Park and Wrigley Field, even if the criteria set out in subparagraph (a) above are not met. Scheduling a postponed game as part of a conventional doubleheader will not be considered a practical alternative.

The Association shall have the exclusive right to approve the additional rescheduling of postponed games as split doubleheaders in circumstances that are not automatically permitted by subparagraph(a) or (b) above.

I like that they don’t say what the difference between a “split” and a “conventional” doubleheader is. I would guess it means split admission.

Paragraph 10:

No Club shall be scheduled, or rescheduled if practicable, to play more than 20 consecutive dates without an open day, or 21 consecutive dates if necessary to accommodate the Hall of Fame Game. A rained-out game may be rescheduled to an open date in the same series, or to an open date at the end of the same series, if (a) the open date is a road off-day for the visiting Club, and (b) the rescheduling does not result in the home team playing more than 24 consecutive dates without an open day, or 25 consecutive dates if necessary to accommodate the Hall of Fame Game.

Paragraph 17 of the same section:

(17) With respect to the rescheduling of any game, except for games rescheduled as split doubleheaders as set forth in Section C(1), any scheduling or rescheduling rule set forth in this Article V may be waived by the secret ballot vote of a majority of the Players on the Club(s) that would be in violation of the rule. Separate votes shall be required with regard to each game for which a waiver is sought. A waiver granted pursuant to this provision, as well as a waiver granted by the Association pursuant to Section C(1), shall not constitute a precedent with regard to future waiver requests. With respect to the rescheduling of any such game, and all games rescheduled pursuant to Section C(1), the Club(s) shall consult with the Association concerning the actual date and time of such rescheduled game. The Club(s) shall use best efforts to notify the Association in advance of notifying the Players on the Club(s) affected.

You can download the CBA here or ambush Brewers player representatives Craig Counsell and Dave Bush for more info.