Differences in documentation from PostgreSQL

[thjbdvlt]

hello :-)

i am starting using AGE so i am currently reading the documentation; i've seen that some content is kind of copy-pasted from postgresql documentation without referencing to it, is it intentionnal (and common in open source softwares)?
plus, it actually differs from postgresql documentation (in a way that looks inexact to me), probably because it is based on a previous version of the documentation.
here is the passage:

The integer type stores whole numbers, i.e. numbers without fractional components. Integer data type is a 64-bit field that stores values from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807. Attempts to store values outside this range will result in an error.

The type integer is the common choice, as it offers the best balance between range, storage size, and performance. The smallint type is generally used only if disk space is at a premium. The bigint type is designed to be used when the range of the integer type is insufficient.

postgresql documentation says that it is bigint that have the range specified here (and not integer). reader can think that bigint type actually goes beyond 9,223,372,036,854,775,807, which it does not.

here is what PostgreSQL documentation says about integer types, which looks similar to AGE documentation:

The types smallint, integer, and bigint store whole numbers, that is, numbers without fractional components, of various ranges. Attempts to store values outside of the allowed range will result in an error.

The type integer is the common choice, as it offers the best balance between range, storage size, and performance. The smallint type is generally only used if disk space is at a premium. The bigint type is designed to be used when the range of the integer type is insufficient.

and about ranges:

integer	4 bytes	typical choice for integer	-2147483648 to +2147483647
bigint	8 bytes	large-range integer	-9223372036854775808 to +9223372036854775807

i undersand that integer is at the same times a type (at the same level of smallint and bigint) and kind of a super-type (which includes smallint, integer and bigint), but i think that citing exactly the current version of the postgresql documentation would be more precise. what do you think about it? (as i am very very new, i would not want to change anything without asking.)

or maybe the documentation is not inexact, and integer data types in AGE are different that in postgresql? if that is the case, wouldn't it be worth to say it explicitly? (and to write it with a paragraph less similar that this one from postgresql)