diff --git a/Elements-and-observables.md b/Elements-and-observables.md
index 4ac2b78..4b9869f 100644
--- a/Elements-and-observables.md
+++ b/Elements-and-observables.md
@@ -32,4 +32,10 @@ Can we realize constraints as geometric objects? For example:
 
 Maybe being subject to a constraint can then be seen as a kind of incidence.
 
-***To do:** Explore ideas for unifying elements and observables in spite of the contrasts described above.*
\ No newline at end of file
+***To do:** Explore ideas for unifying elements and observables in spite of the contrasts described above.*
+
+## Questions/Cautions
+
+* What is the status of a "second-order" constraint, e.g "these two observables are equal"? Are they just additional Constraints, even though their slots are other Constraints? If we use the "filter Constraints by an Element" metaphor, and we select a plane P and it shows us the three angle Constraints it is involved in and one of those angle Constraints theta is further constrained to be equal to another angle rho that does not involve P, does that equality constraint show up? Does rho itself show up?
+* Could a Scalar be an element? I.e., a "free-floating" real number?
+* What is/should be the mechanism for making numerous angles identical be (say)? By experience, using a bunch of equality constraints and relying on transitivity becomes cumbersome and a bit hard to "see what's going on". Those interfaces that allow one to have "named quantities" and then use those "named quantities" as the values of other parameters have felt more understandable, and easier to manipulate.