these are also spectator ions. spectator ions don't participate in the actual chemical reaction.
Suppose we have this reaction:
NaOH + HCl --> NaCl + H2O
If we separate each substance into their component ions (with the exception of water), we will get the following:
Na+ + OH- + H+ + Cl- --> Na+ + Cl- + H2O
the spectator ions don't participate in the actual reaction, and they appear in both sides in the chemical reaction. The spectator ions are Na+ and Cl-. Removing the spectator ions gives us the net ionic reaction
H+ + OH- --> H2O