About definition of common placeholders for descriptive items in yml file

<boolean>

Indicates a Boolean value that can have either "true" or "false" values.

<duration>

Indicates the duration that matches the following regular expressions:((([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?|0)

<filename>

Indicates a valid path in the current working directory.

<host>

Indicates a valid string consisting of a host name or internet address and an optional port number.

<int>

Indicates an integer value.

<labelname>

Indicates a string that matches the following regular expression:

[a-zA-Z_] [a-zA-Z0-9_]*

<labelvalue>

Indicates a Unicode string.

<path>

Indicates the path of a valid URL.

<scheme>

Indicates a string that can use either "http" or "https" values.

<secret>

Indicates a normal string that should be kept secret, such as a password.

<string>

Indicates a regular string.