A custom order is any request for a personalized item.  This includes:
invitations
announcements
wall art
wedding stationery
event materials (signs, favor labels, etc.)
any emailed request for an item not found in the shop
Cool update: most of my custom orders have now become digital files!  First, it's much more environmentally friendly - always a good thing!  Second, the customization process is much faster and much of it can be done by you, so there's no email back-and-forth with proofs and changes. (Although if you'd like to email me just to chat, feel free! I've made many lovely friends while creating custom orders.)  And third, with Covid and lockdowns and everything going on lately, keeping things online-only means they're pretty germ-free.  And I like germ free.
If you're curious what kind of things I've made, check out this gallery of previous custom orders.