  It is well known that sets of $p$-capacity zero are removable for bounded
$p$-harmonic functions, but on metric spaces there are examples of removable
sets of positive capacity. In this paper, we show that this can happen even on
unweighted $\mathbf{R}^n$ when $n > p$, although only in very special cases. A
complete characterization of removable singularities for bounded
$\mathcal{A}$-harmonic functions on weighted $\mathbf{R}^n$, $n \ge 1$, is also
given, where the weight is $p$-admissible. The same characterization is also
shown to hold for bounded quasiharmonic functions on weighted $\mathbf{R}^n$,
$n \ge 2$, as well as on unweighted $\mathbf{R}$. For bounded
$\mathcal{A}$-superharmonic functions and bounded quasisuperharmonic functions
on weighted $\mathbf{R}^n$, $n \ge 2$, we show that relatively closed sets are
removable if and only if they have zero capacity.
