It’s a good point — how do we handle this in a scenario where we have people who are ‘newbie’ app or website users versus those who have invested time in ‘learning’ the product. The answer is that design is contextual and the context will vary. If you are expecting people to use the ‘settings’ icon and use this as part of their onboarding, good luck if you don’t have a label. If the ‘settings’ is hardly ever used, it might not be such a problem. There are some solutions explained here (https://ryanhouk.medium.com/why-good-bad-design-guides-arent-always-good-for-iconography-48e2089ffbce) but my feeling on this is pretty concrete — unless you have a very good reason to eschew labelling things, you cannot reliably use an icon (especially when it isn’t learned elsewhere) without a label. One could argue that for specific audiences, they have already ‘learned’ what the settings icon ‘normally’ looks like. However, most people make assumptions about their audience that aren’t true and this one would need validation, before deciding to use an icon without a label. It’s easy enough to test this out and validate it with your target audience. If in doubt, add a label.