Questions specific to the HTC One X+ handset, not the HTC One X or HTC One XL. If your question could also apply to other devices, mention the phone in the question itself instead of using this tag.
The HTC One X+ is a slight hardware update over the HTC One X, with more internal storage, a newer version of the Nvidia Tegra 3 SoC.
As with all device-specific tags, only use the tag if your question only applies to this particular phone model. If your question could apply to all HTC phones, use htc instead. If someone with a different phone might have the same question, then by all means mention in the question that you have an HTC One X+, but don't add the tag.