Who says Barchu at the end of davening?

Question

Here in Israel, at the end of Shacharit most days, and Maariv all the time, someone says Barchu. In Nusach Sefard, it's before Aleinu; after in Nusach Ashkenaz. It is generally said by someone who just said Kaddish, though if no one said it, the chazzan does.

When there are multiple people who said Kaddish, how do they know which one should say Barchu? Usually there is no conflict; someone just says it. Once in a while there'll be two, or someone will need prompting. But in the average case, who is supposed to say it, that the others let him?

Answer 1

There's usually some unwritten rule for this. Something like:

• Some Aveilim are Makpid to say both Borchu's - so they always take it.

• Or else it's given to the unlucky fellow who didn't get to be Chazzan - since the Chazzan already said a Borchu. If there's no 2nd chiyuv then the Chazzan will say it.

• If a Sefardi also said Kaddish, and he's anyways going to say Borchu, then the other candidates don't say it.

And if you look carefully, there's usually a conversation going on between the Kaddish-sayers - using head-nodding - while they are saying (or right after) that final Kaddish.

Answer 2

The Mishna Berura (132:10) makes little distinction in the importance of a mourner not only saying kaddish, but Barchu as well. It could very well be that just as many mourners can say kaddish in unison, so too can individuals say Barchu together:

י) קדיש יתום אחר עלינו - שהרי לעולם צריכין לומר קדיש אחר שאמרו פסוקים ובעלינו יש ג"כ פסוקים וצריכים קדיש אחריו אלא שנהגו בקדיש זה להניחו ליתום שמת אביו ואמו מפני שיש יתומים קטנים או אפילו גדולים שאינם יכולים להיות שלוחי ציבור ולומר קדיש וברכו אחר אביו ואמו [שאם היו יכולים להתפלל לפני העמוד זהו טוב יותר מאמירת קדיש] וכבר ידוע ממעשה דר' עקיבא תועלת הגדול שיש למת כשיש לו בן האומר קדיש וברכו וביותר בתוך שנה ראשונה לכך תקנו והניחו קדיש זה שאין צריך שום דבר יותר ליתומים הן קטנים הן גדולים.