Every page (except the ones that are numbered and dated wrong) carries the word HAFSAKA. It means a break, and refers to the one or two Shabbatot between Sh'kalim, the first of the Four Parshiot and HaChodesh, the last of the Parshiyot. The rules for when each parsha is are such that the four parshiyot cannot be on 4 consecutive Shabbatot. Usually, five is sufficient; sometimes there are 2 hafsakot, making 6 Shabbatot.

There are 4 possible arrangements of the Parshiyot in our calendar. Rosh Chodesh Adar (referring to the Adar right before Nissan and referring to the second day of Rosh Chodesh. In other words, 1 Adar or 1 Adar Bet). If Rosh Chodesh is a Wednesday, as it was this year, then the previous Shabbat is Sh'kalim and the following Shabbat is a break. That break is the 4th of Adar. This kind of year has been code DALET-DALET, for Rosh Chodesh on DALET, a.k.a. Wednesday, the Hafsaka will be DALET, the 4th of the month.

Or, Rosh Chodesh can be Monday. Such a year would be coded as BET-VAV, indicating that the break falls on the 6th of the month.

Or, Rosh Chodesh can be on Shabbat. Then Sh'kalim will be on that Shabbat Rosh Chodesh, the following week, without a break, will be Zachor, the Shabbat after that will be Purim in Yerushalayim (and will be counted as a break from the Four Parshiyot), then Para and HaChodesh. Such years are coded ZAYIN-TET"VAV, meaning Rosh Chodesh on Shabbat and the Hafsaka on the 15th of Adar. Next year, 5761, is scheduled to be that kind of year. That also means Purim M'shulash, Triple Purim in Jerusalem, and the Seder will be on Motza'ei Shabbat. Lots of "fun" laws and customs to learn about and review. Watch for announcements for shiurim on those topics.

And the fourth possibility is Rosh Chodesh on a Friday, VAV. In those years, the following day will be a break, the 2nd of Adar. The 9th will be Zachor, the 16th will be another break, then the 23rd will be Para and the first of Nissan will be a Three Sefer Torah, 3 kugel Shabbat. Those years are coded VAV-BET-YUD"VAV.

Of course, when the Sanhedrin is reestablished, the calendar becomes more flexible and all the stats and rules and codes, and observations fall apart and we will deal with new stuff.

With a Sanhedrin and a Beit HaMikdash, BB"A, we probably won't (might not) have Shabbat P. Sh'kalim - we'll have the mitzva of Machatzit HaShekel. Zachor will continue. Para and HaChodesh will be "real" again.