1A. Pybro's Purpose
As a Pybro you must stay near your engineer(s) at all times, Either in their nest or if multiple nests you are excused from the rule when traveling between nests to make sure your Engineer(s) is/are safe, If there is already a Pybro protecting that nest then you are to stay out of that nest except to protect in their absence.

1B. Showing Respect
As a Pybro you must respect all engineers unless they attempt anything aggressive toward your own team's Engineers. If they attempt aggressive actions toward your team's engineers then smash only what harmed your engineer. (This includes teleporter exits if they telefragged your Engineer(s))
Though not required, it is strongly suggested that you respect Pybros on the enemy team by giving them a non-damaging taunt (A High-Five or Fist Bump if you are able to.), Though if they feel unsafe with you in the presence of their Engineer, It is wise to respect their worries and return to protecting your own Engineer's nest or find a detour if needed to get back to your Engineer's nest.

2A. Spies
With the exception of Spycrabs, Boxspies, and Observer Spies, you must assume all spies are a threat to your Engineer and treat them accordingly. In the event of Spycrabs you should make an attempt to guide them safely away from the nest using sound (as Spycrabs have very bad eyesight), In the event of Boxspies avoid airblasting them or knocking them back in any way that could cancel their taunt, Boxspies do not like being disturbed, And in some cases disturbing a Boxspy can cause them to die, And due to them being an endangered species alike the Spycrab, it is detrimental that you avoid harming them, Lastly in the event of Observer Spies you should let them be aslong as they do not uncloak (If their Cloak & Dagger runs out of cloaking they are still exempt from Spy aggression, Only attack if they right click to lower their watch, Which is indicated by them unlcloaking with only a single quieter uncloaking sound as opposed to the loud cloaking sound that is made when your cloak meter is out)

2B. Other Friendlies
Other friendly classes should not be provoked, And you should make an attempt to inform your Engineer if they have yet to be already informed that a friendly is incoming so they are sure to wrangle their sentry while the friendly is in the presence of a sentry.
If you are unsure if they are a friendly or not, Please consult The Almighty Species Guide

2C. Extra Chances
Before giving someone a second chance to not attack your Engineer, Please consult your Engineer to see if they are okay with giving them another chance to prove themselves to be friendly.

2D. Empty Sentries
If your Engineer is a friendly Engineer and they make an Empty Sentry, It is a Pybro's job to work tirelessly to make sure that sappers are destroyed so that the Engineer doesn't accidentally hit it an extra time and give the sentry ammo. If someone destroys a Empty Sentry once you can give them an extra chance if they didn't know it was Empty and apologize for it. If they destroy it after that, Then they are disallowed from second chances and are now kill-on-sight to you and other Pybros.

3A. Primary Weapons
To ensure you are protecting your Engineer to the best of your capabilities, Use the Degreaser if they are under heavy projectile fire to increase the airblast speed, Stock if they are facing some projectile fire for airblast ammunition efficiency, Or the Dragons Fury if they are facing hitscan fire but might face projectile fire so you still have airblast in-case necessary, . If there is already a Pybro protecting the nest, You are excused to use the Phlogistinator or Backburner for backing fire for the other Pybro.

3B. Secondary Weapons
To ensure you are protecting your Engineer to the best of your capabilities, Use the Stock Flare Gun if you are facing heavy classes in order to kill them faster, The Scorch Shot if you are facing lighter classes or spies to delay their assault with knock-back, The Detonator if you are facing just Spies or on a map that has lots of death pits so that you can jump around to get to advantaged ground when combating those who harm your engineer, You are required to use the Mannmelter if you are using the Phlogstinator or Backburner in order to always be capable of extinguishing your Engineer. The Gas Passer can also be used in some circumstances if you already have another Pybro protecting the nest with you so that you can Spycheck quicker (though if you are using the gas passer you must be committed to using it to protect your Engineer because of the long meter wait time.).

3C. Melee Weapons
To ensure you are protecting your Engineer to the best of your capabilities, Use a weapon capable of removing sappers at all times, The Homewrecker is preferred, But if your Engineer is nesting near water you are allowed to use The Neon Annihilator to fend off classes like Spies who might attack your nest.

3D. Engineer's Weapons
If your Engineer has the Gunslinger and Frontier of Justice aswell as one or more kills with the current Mini-Sentry, Then don't attempt to save the Mini-Sentry as to allow the engineer to get Crits, Which can be vital to their survival in the event that you are taken down.
If your Engineer has the Short Circuit, You are free to use the Backburner or Phlogistinator, But you are required as always to use the Mannmelter so that your Engineer never has to fear dying of aftterburn.

4A. Helping Your Engineer Strategize
When possible, Always help inform your Engineer how they could better place their structures to help you help them.
These include but are not limited to:
Sentry Distancing, All sentries should be 600HU (Hammer Units) apart from eachother. This prevents splash damage from spreading between them.
Dispenser Distribution: All dispensers should be different distances from the frontlines so that if one is taken down, your team isn't pushed back near as far as they would be if both dispensers were destroyed.
Teleporter Tinkering: Teleporter Exits should always be placed facing directly away from a wall so that Spies cannot kill people as they enter the teleporter.

4B. Spies
It is polite to inform your Engineer if you spot a Spy, even if the spy is friendly you should make them known to your Engineer, The only exception to this is Observer Spies because they like silence, So it's better to let Observer Spies be.

4C. Other Pybros
It is common courtesy that if you see a enemy Pybro in your nest, to use the Voicemenu option "Spy!" on them and then to use the "Sentry Ahead" Voicemenu option (If there is a non Empty Sentry)

4D. Other Friendlies
If you spot other friendlies it's reccomended to use the "Thanks!" Voicemenu option and shake your head up and down to indicate you come in peace. So that they don't feel intimidated by your defensiveness of your Engineer.

5A. Engineer Leaving
I know it may be hard, But if your Engineer leaves and you don't have another Engineer to defend, Then you should switch to Engineer in order to carry out what they set out to do before you in honor of your now gone comrade.

5B. Engineer Gaming
If you spot an Engineer Gaming, As a Pybro you are required to add them as a steam friend as a sign of respect for their Engineer respect or dedication, As your job as a Pybro is to help make Engineers better informed and keep them safe from harm. So to be a true Pybro you must first have respect for Engineer Mains and Engineer Gamers.