Cuban bread is difficult to find outside of Florida, but French or Italian bread can be substituted.
On the substance, sure: the mandate is merely a means to an end, and there are other means that could be substituted for it.
We took their spirit, and substituted the spirit in the bottle.
early 15c. in transitive sense, 1888 as intransitive, from Latin substitutus, past participle of substituere (see substitution). Related: Substituted; substituting.
"one who acts in place of another," early 15c., from Old French substitute and directly from Latin substitutus, past participle of substituere (see substitution). Team sports sense is from 1849.