They placed a matzeivoh on the frishe kever of Reb Volf. In Chabad we're makpid to do so at the end of the shivah, no matter what time of year, and no matter if more people would attend at a later, more auspicious time. If you'll look closely you'll notice something at the very top of the stone; a line written in handwritten script, and different from the rest of the wording. What happened was as follows: When Reb Volf's Rebbetzin was niftar some 29 years ago he sent in a nusach for her matzeivoh, referencing himself as only "Reb Menachem Zev HaLevi." The Rebbe added the words you see written here, and added "if he will agree." Reb Volf, of course, of course agreed, and that's how her matzeivoh was engraved. Now, when Reb Volf was niftar, I believe they had a dilemma as to what to write for him, since he so refused to be addressed by such titles, yet the Rebbe wanted him to be addressed as such. So they came up with this very clever idea, with which they'd be mekayem divrei haMes and divrei HaRav shechayim VeKayomim Lo'Ad. I believe we'll see alot more of this in the future in Chabad. A gut feeling, that's all.
The nusach with the Rebbe's additions on the bottom.
