Here’s what I found.

Count
143,859.¹
Full table: https://unicode-table.com/en/#basic-latin
Methodology
This short article assumes that by now, every useful/usable/commonly-used character has been encoded and added to the unicode standard.
This is not necessarily the case. In fact, “Unicode standard doesn’t freeze, it continues to evolve.”²
Definitions
Character (computing): In computer and machine-based telecommunications…
Here’s what I found.

Count
97.
Entire lit: https://github.com/aa-ag/counting_stuff/blob/main/http_status.txt
Definitions
HTTP: The Hypertext Transfer Protocol is an application layer protocol for distributed, collaborative, hypermedia information systems.¹
(HTTP) Status Codes: are issued by a server in response to a client’s request made to the server. It includes codes from IETF Request for Comments…
Here’s what I found.

Count
1635.
Entire list: https://github.com/aa-ag/counting_stuff/blob/main/formats.txt from https://en.wikipedia.org/wiki/List_of_file_formats
Definitions
A file format: A format for encoding information in a file. Each different type of file has a different file format. The file format specifies first whether the file is a binary or ASCII file, and second, how the information…