Using the API call "g_form.addOption" in a lookup select box filters out duplicatesIssue <!-- div.margin { padding: 10px 40px 40px 30px; } table.tocTable { border: 1px solid; border-color: #e0e0e0; background-color: #fff; } .title { color: #d1232b; font-weight: normal; font-size: 28px; } h1 { color: #d1232b; font-weight: normal; font-size: 21px; margin-bottom: 5px; border-bottom-width: 2px; border-bottom-style: solid; border-bottom-color: #cccccc; } h2 { color: #646464; font-weight: bold; font-size: 18px; } h3 { color: #000000; font-weight: bold; font-size: 16px; } h4 { color: #666666; font-weight: bold; font-size: 15px; } h5 { color: #000000; font-weight: bold; font-size: 13px; } h6 { color: #000000; font-weight: bold; font-size:14px; } ul, ol { margin-left: 0; list-style-position: outside; } --> Symptoms Using the API call "g_form.addOption" in a lookup select box filters out duplicates Release All Cause This is implemented by design to address PRB620011, here is the code preventing duplicates: Looks like we have deliberate duplicate checking in addOption: var len = control.options.length; + + // validate that duplicate choice label is not being added. + for (i = 0; i < len; i++) { + if (control.options[i].text == choiceLabel) { + return; + } + } Resolution Working as expected, and it cannot be change since this is within the source code itself