Cargo Bullseye

A cargo bullseye is a form of marking on cargo containers and cargo-carrying vessels which allows workers and emergency personnel to quickly ascertain any dangers inherent in the cargo carried therein. They are mostly used in commercial or industrial applications where large amounts of a given substance will be moved at once. On the other hand, military cargo craft will often eschew cargo bullseyes, as they can provide valuable intelligence to enemy raiding parties.

Morphology

As the name implies, the most common form which a cargo bullseye takes is a series of concentric circles in reflective colors. This shape was chosen because it has rotational symmetry. Airships, skystations, and some skymoths spin to create artificial gravity within the otherwise weak or neutral gravity of inflection layers and commissures, and, therefore, a good warning sign should be readable in any orientation when attached to the nose or tail of such vessels. When thus affixed to a vehicle, a cargo bullseye also features a series of stacked, cylindrical markers extending vertically from the center, allowing the bullseye to be seen even when the vessel is approached edge-on; for the purpose of these markers, the end of the stack closest to the vessel's hull is considered the 'bullseye's' center.
The rings (and stacked markers) are used to denote the types of hazardss presented by a given cargo and the severity of danger involved in handling the cargo. Each ring indicates a separate category into which a hazard might fall. Each hazard is given a color-based indicator based on its severity, starting with black (least severe), to red, orange, yellow, green, blue, indigo, violet, and white (most severe). These colors are also given contrast (via varying levels of white striations) so that their meanings can be discerned even in monochrome or low-light conditions (i.e. in the Distal Tesseract). All these indications are based on the end results of the cargo being interacted with, not necessarily its base form - for example, a compound which is inert except that it releases a toxic gas when exposed to water would be rated for this byproduct, not its unreacted form.
From the inside ring to outside ring, the hazard categories are:

1. Pole - The innermost circle is unused, as it can be hard to read from a distance.


2. Pressure - This ring indicates the pressure of the cargo, from red indicating sea level atmospheric pressure to violet indicating extremely high pressure. Black is seldom used, as it represents a vaccuum, while white may indicate unmeasurably high or dangerously variable pressure. This marker is important in airship applications, especially vessels like 4GW "Dewstar" Liquid Freighter Aerostats, as the pressures involve have important implications for load balancing and buoyancy considerations.


3. Flammability - This ring indicates the relative inflammability of the substance contained. Strong oxidizers, because they can often by pyrophoric in the environment, are also often highly rated in this category. Substances above green require an armed escort, as accidents involving them may constitute violations of the Medial B Accords in some circumstances.


4. Corrosion - This ring indicates the relative ability of the cargo to attack the chemical structure of substances it comes into contact with, though this is measured independantly of flammability.


5. Toxicity - This ring indicates the relative toxicity of the cargo, independent of what is denoted in the corrosion and exotic categories, to plant and animal life (especially sentient species. Substances above green which also have an exotic marker will often be 'persuaded' to have an escort by Manifold Conservation Society officials, as these might be used as chemical, biological, or radiological weapons in the wrong hands.


6. Exotic - This ring is most often left unused, but can be used to denote additional hazards not covered by other categories. Black, red, orange, and yellow markers indicate the sorts of special firefighting compounds required to fight a burning material, with the latter of these colors generally indicating an increasing ability on the part of the material to scavenge oxygen to continue buring despite firefighting efforts. Green indicates a one-time or point-based radiological exposure risk (i.e. cyclotrons), blue indicates a one-time biohazard exposure (i.e. manure), indigo indicates a spreadable radioactive contaminant (i.e. neutron-activated scrap from the Northwoods Botanical Research Facility), violet indicates a contagious or invasive biohazard (i.e. Distal polyps), and black indicates dangers for which there is no clear quantification (i.e. the Menger Catalyst or absinthite).


7. Load - This ring is not solid. Instead, reflectors are placed in this ring to indicate the relative locations of loads concealed within the vessel or container, while the color indicates the relative mass of these loads. This information is mostly useful for loadmasters and pilots, but it can also come in handy for firefighters looking for the source of flames or, for hazardous-condition salvage reclamation techs looking to find (or avoid) certain kinds of cargo within a wreckage.

Syntax

A vessel may use more than one cargo bullseye if multiple different hazardous materials are to be carried. In situations where this is impractical for some reason, the most severe color indication must be used in each category so that emergency personnel are best prepared to deal with the cargo in the event of a crash, spill, or other accident.