All permutations are, in other words, all possible combinations of words composed of the characters of the original word. If you want to generate all permutations of a word, e.g. ABCD in advanced mode, enter this word in the field "Set of characters that can appear in the code", and then set "Single code length" to the length of the entered word (in this case 4), and "Number of codes to generate" to the number of possible combinations that can be obtained from the selected generator configuration (in this case 256). The exact number of possible combinations can be found in the description of the field "Set of characters that can appear in the code".
Every computer on the Internet has its own IP address that uniquely identifies it. The most common way to write an IPv4 address is to represent it as 4 numbers from 0 to 255 separated by dots. The list of IPv4 addresses can be useful when testing various types of security or access control mechanisms.
When testing systems in which resources are marked with a date, a set of random dates may be useful. One of the most popular date formats in IT systems is the YYYY-MM-DD format, which means that at the beginning there is a four-digit year, then after a dash a two-digit month number with a leading zero, and then after a dash the day of the month also with a leading zero.
Dates and times in IT systems are often written in numerical form using the so-called Unix timestamp. A Unix timestamp is the number of seconds since January 1, 1970 UTC. Unix timestamps are a digital standard for denoting an exact, universal time.
The MD5 message-digest algorithm is a widely used hash function producing a 128-bit hash value. For greater readability the 128-bit (16-byte) MD5 hashes are typically represented as a sequence of 32 hexadecimal digits.
SHA-1 (Secure Hash Algorithm 1) is a hash function which takes an input and produces a 160-bit hash value known as a message digest. For greater readability the 160-bit (20-byte) hashes are typically represented as 40 hexadecimal digits.
A very common practice when developing software is to mark its successive releases or versions with a unique code, the so-called version number. This makes it easy to determine whether the software is up to date (has the latest version number) and to refer to a specific release when problems or bugs are reported. One of the most common ways of numbering software versions is semantic versioning, the so-called "SemVer". The standard version number must take the form X.Y.Z, where X, Y and Z are non-negative integers and must not contain leading zeros. X is the major version, Y is the minor version and Z is the patch version. Each component must grow numerically. For example: 2.19.0 → 2.20.0 → 2.20.1 → 2.21.0.
Car tires are described using a special code, for example 195/65R15 where 195 is the tire width given in millimeters, then there is the / sign followed by the tire profile which determines the height of the tire sidewall, given as a percentage of the width (here 65% from 195 equals 126.75 mm). Then there is the tire type designation in the form of a letter, here R stands for radial tire. The last element is a number indicating the size of the rim that the tire fits on, given in inches, in this example the tire fits a 15-inch rim.
Colour coding can be implemented in different ways. One of the most popular of these is RGB within which each colour is represented by a mixture of three different colours Red, Green and Blue in which each colour is stored as a value from 0 to 255 depending on its intensity. For ease of readability and portability, these numbers are usually written as set of hexadecimals with # prefix.