Let $\mathcal{K}$ be a $2$-category. Is there a special name of those objects $B \in \mathcal{K}$ which have the property that the category $\mathrm{Hom}\_{\mathcal{K}}(B,C)$ is essentially discrete for all $C \in \mathcal{K}$? This means that for every two morphisms $f,g : B \to C$ any $2$-morphism $f \to g$ is an isomorphism, and it is unique if it exists.


Also, is there some intuition what this property actually means, intuitively?


Assuming that $\mathcal{K}$ has more properties (such as the existence of certain limits), can we simplify the property perhaps to some "internal" information of $B$?


Here is the example which motivates my question: Consider the $2$-category $\mathrm{Cat}\_{c\otimes/R}$ of cocomplete $R$-linear tensor categories and let $A$ be a commutative $R$-algebra. Then $\mathrm{Mod}(A) \in \mathrm{Cat}\_{c\otimes/R}$ has this property, since $\mathrm{Hom}\_{c\otimes/R}(\mathrm{Mod}(A),\mathcal{C}) \simeq \mathrm{Hom}\_R(A,\mathrm{End}(1\_\mathcal{C}))$ and the latter is a set. I have recently proven that $\mathrm{Qcoh}(X)$ has this property as well, where $X$ is any quasi-compact quasi-separated $R$-scheme. When $X$ is an algebraic stack, usually $\mathrm{Qcoh}(X)$ doesn't have this property.



"discrete" objects of a $2$-category
I would call those objects "codiscrete" or "co-0-truncated", since "discrete" and "0-truncated" are used for the dual property, e.g. [here](https://ncatlab.org/nlab/show/discrete+morphism) and [here](https://ncatlab.org/michaelshulman/show/discrete+object). It's equivalent to saying that $B$ is equivalent to the copower $B \odot (\cdot \rightrightarrows \cdot)$.


