
There are three types of data: sensitive, public, and unclassified. Sensitive refers to data that is in an unencrypted form that should not be shared with people who are not authorized to see it. Public is data that anyone can see at any time without any restriction or scrutiny from the government or other agencies. Lastly, unclassified data is still information that needs to be protected from unauthorized access but the government does not feel like it needs to be examined as closely as classified information does.
Each government agency has a level of importance attached to it. Depending on the level, the agency can have as many as five levels of classification (Confidential, Secret, Top Secret). Data is classified based on what type (and how much) of danger there is if that data were to fall into the wrong hands.

All levels have a specific color code assigned to them and that color code is what identifies the level from the others in any situation or location. For example: the FBI is a high level agency with Secret and Top Secret being some of the levels. Top Secret is always blue. All personnel working for the FBI must carry a special pass identifying them as being an authorized member of the bureau.
These passes are normally ID cards that require a thumbprint or hand print to get through certain doors, gates, etc. Some government agencies have facial recognition technology for those same situations and places.
Data can be classified in some cases by date but it usually happens when something occurs at a certain date and time period such as 9/11 or Pearl Harbor. When that is done, data that was collected before or after those dates will automatically be classified at whatever it was before those dates occurred.
There is another method of classifying data that does not pertain to the levels given by the government. This method is used by agencies or companies where there isn’t a specific hierarchy of access to information but rather assigns a level of importance based on when it was collected.
These types of systems are used in military operations involving soldiers, commanders, etc. The purpose is to give general data to all parties in the operation without giving out specific data that might be regarded as classified information.
The person or persons who collect and store this type of information must make sure that they have no writing devices (pen, pencil, etc. – even pastels) in their possession while doing their work. The idea is that the data should not be read or written down by anyone else.

If the data is to be placed on a computer, it must also be encrypted using software at either the hardware or software level. This encryption must also not use any special characters (like “@”, “#”, etc.) in the code that makes up these programs and files. This is done for two reasons: the first reason being that if one of these special characters were to exist in a file name or a file extension, an error could occur which would make it easier for an intruder to obtain information from that computer. The second reason is because those special characters can be a dead giveaway that something is being hidden.
Sensitive data can be sent electronically but that data must then be stored on a hard copy or printed file. This doesn’t mean the data cannot be sent over the web – it just means that the information has to be stored on paper for safekeeping and possibly a backup should something happen to the computer or network where the data is stored.
The names of various government agencies or programs do not have to have their classification levels attached to them. Names of people, products, places, etc.