A crow's foot would be scratches (or gouges) in the concrete with a point at the drill hole.
Will look similar to the track a crow would leave in dust or mud.
First catch a crow, then look at it's foot.
Alternatively, think of a capital K.
I would be inclined to think that the crow's foot was first and the drill hole added later, but the opposite may be proven.
Paul in PA
On this side of the pond crow's foot are very often used in NYC for horizontal control, not BM's. They cut in marks with diamond blade cutoff saw. The center line of the crows foot is aligned with the property line or building line, and are cut into the concrete curb or sidewalks.
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They were very popular in the City of Paterson NJ on the bluestone curbs and many remain to this day.
This is probably already well known, but the word benchmark would have come from a metal piece being put in the crow's foot I posted above which provided a bench for a staff to rest on.
This side of the pond a crows foot would be a benchmark.
That's a weird looking crow on that side of the pond.
Our crow's foot-print . . .?ÿ
When I was in college, we learned to use crow foot quill pen for fine lines and small lettering.
You may not find something as elaborate as the marks shown in earlier post. It could be something as simple as this.?ÿ
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The drill hole will be in the point or intersection of the two lines.?ÿ
That's what I set when a point hits on a concrete surface. Mine looks more like a Y with a drill hole in the center. I always figured it was one less line to chisel verses setting an X?ÿ
Around here a crow's foot is most often used when there's something (e.g. a building face) that prevents a cross from being cut.