Which insignia position is used for lower-ranking officers in service dress?

The insignia position for lower-ranking officers in service dress is typically found on the shoulders. This placement allows for a clear and official representation of rank, distinguishing lower-ranking officers in a formal uniform setting. The shoulder insignia is visible and is an established standard across various military branches, facilitating ease of recognition by peers and superiors alike.

In contrast, the other positions mentioned are either not standard for officers or are designated for different purposes. For instance, insignia placed on the collar is more commonly reserved for enlisted personnel rather than officers. Both sleeves generally display unit patches or certain types of insignia but are not specifically for rank identification. Lastly, having insignia only on the left sleeve does not align with the traditional insignia placement for officers, as the standard practice places them on both shoulders instead. This structure maintains uniformity and consistency across military dress codes.