Bruce Janson wrote:

I had assumed that those who referred to their in-orbit experiments
as being in "microgravity" did so because they were being careful to
acknowledge that despite their free-fall relative to Earth their
experiments might still feel the (micro) gravitational attractions
of other objects such as the surrounding spacecraft and nearby astronauts.

Those gravitational attractions are negligible. The micro-g they refer
to is due to the fact that most of the Station does not lie precisely on
the orbital path of the Station center of mass. The orbital velocity is
different at different altitudes, so portions of the Station which are
above or below the center of mass will feel a radial acceleration away
from the center of mass. Portions of the station which are to the left
or right of the center of mass will feel a horizontal acceleration
toward the orbital plane of the center of mass.