https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-destroyicon

It is only necessary to call DestroyIcon for icons and cursors created with the following functions: CreateIconFromResourceEx (if called without the LR_SHARED flag), CreateIconIndirect, and CopyIcon. Do not use this function to destroy a shared icon. A shared icon is valid as long as the module from which it was loaded remains in memory. The following functions obtain a shared icon.

• LoadIcon
• LoadImage (if you use the LR_SHARED flag)
• CopyImage (if you use the LR_COPYRETURNORG flag and the hImage parameter is a shared icon
• CreateIconFromResource
• CreateIconFromResourceEx (if you use the LR_SHARED flag)

Oh, neat. Thanks.