This page covers visible public markings that are for slaves, but only some apply to dog slaves, for example might be quite common/traditional to have ownership chain locked on you slaves ankle but hard to replicate that into the dog world.
Like you don't have a harem of dogs (unless ya really lucky) where as you do of maidens. Since the female slave is a house hold object you would have it fitting into the rest of your possessions. Like it would not be poorly dressed as that would mean YOU were poor.
A slave is a status symbol to be shown off along with the car and any other possession. Of course this can vary where the slave as a solid Silver chain that is soldered closed to a stainless steel chain that is pad locked.  Following this would be the  slave number or other property identification.

Slave Registration Number

Who the owner is and the slave number. Once snag with putting "Property of Topdog1" on your slaves neck is what happens when he is no longer your slave?

The slave registration number is of the form 000-000-000 however it is often

This is where it benefits to have a slave register  where the slaves can move far more freely and connect  or reconnect with different owners, but the slave number remains constant - much like a passport ID. You can have the mark in a place where no one is gonna look. There is little chance that anyone is going to look of your feet. Tho it is common to tattoo a dog on either his ear or on his leg.

Tattoos for the Office.

In this example you can have the tattoo  as a bit of art that is normally covered by your wrist watch and office shirt sleeve. So you could have your slave number tattooed on you what do they know! Likewise  having at tattoo on your back is fine. If you are wearing a white office shirt then what might they see, a dark patch so they might want to see it. Usually because they always wanted a tattoo.
They will be the people with a tiny butterfly on them, not a statement.
There is an expression called "Front it Out".
This is where you act like the real thing - or your front/cover is blown.
So if you act like it is no big deal then why would it be to them? If you start begging "please don't tell" and blush then they might think something in it.

It is your body do what you want with it.

There is one thing getting your neck barcode tattoo when you are kneeling cuffed on the floor head locked between Masters knees.
Its another thing when you are still on probation in your job and they are looking for any reason to get rid of you, or when they are take the piss out of you and you are not as strong without your Master around.  Its not easy being a slave. One of the jobs of the Master is to give the slave inner strength.
This is not always possible if the slave only flies into to see you each month versa being there when he needs you.

You have to be mindful of your working environment and the labour laws of your country. As a contrast there is a vast difference in the labour laws between  France and the USA.
 

Office Casual Tattoos

Likewise if this is who you are you might want to look at different careers. Like having sicko tattoos on the arm of your dentist my make you a bit nervous!

But have you noticed how many people working in tattoo and piercings shops have tattoos and piercings. 
What do your Customers expect you to be?

If you work in an industry that is creativity and individualism  is the norm then it is sort of expected. An example is in the web industry or hair stylists, if you want something unique, creative and individual you might expect that person to have those qualities.

On the other hand you don't expect that from Accountants, Lawyers, Bankers - that is you have a stereo-type about them. If they fit into it, then everyone is happy otherwise you have to be discrete. So basically you need just a bit of preparation

 

Lip Tattoos

All racehorses are required to have a lip tattoo for identification purposes prior to racing.   Any of the racing breeds can have a lip tattoo if they were raced. This tattoo positively identifies the horse and its owner through the animals  registration papers.

Lip tattooing is another form of "branding" an animal and involves having a tattoo made of letters and numbers put on the inside of the lip. The downside regarding lip tattoos are that they are not visible without flipping the lip up, they can fade with age and many times they are not readable due to mottling on the animal lip.
 

 

These tattoos are more about statement, this is what I am versa who I belong to. Still a powerful statement. You can see that this is a bit more sublime, than the foot tattoo for example. 
It is moving towards wanting a statement right down to your genetic code.

This is what I am to the core!