For the purpose of this question I'm picking UGC, UGA and UGG codons (Cys, Stop and Trp aa's) so that the 3rd position of the codon really makes a difference (if it does).
I know there are other pairings out there but to keep it really simple for myself I derived the following tRNA anticodons to match the codons using these rules: G pairs with C or U, C pairs with G, U pairs with A or G, A pairs with U, I pairs with A, U or C.
UGC: ACG or ACI anticodons
UGA: ACU or ACI anticodons
UGG: ACU or ACC anticodons
My question is (assuming I did my work correctly) if there are multiple possibilities for anticodons to match with each codon how would we know which amino acid will attach to which anticodon? Take for example the ACU anticodon that could potentially match with UGA or UGG codons which codes for STOP or Trp. Wouldn't there be a discrepancy/confusion on which to code for?