For most HR systems only 3 general types of documents are useable.
It doesn't matter if the document is being kept by your companies system to be used for internal advertisement of jobs, or for proposal writing; or if it is used to store applicants resumes. Text and word processing types allow the user of the system to massage it. Every contract proposal I have been involved in has required different resume formatting: specifically font size, and margins; plus maximum length requirements.
Many times the system asks the applicant to cut a paste parts of the resume into a text box. Some want the entire resume as a text file. Many experts advise applicants to make sure the resume still looks good as a text file.
The word processing option does allow some variations as long as the user can ingest it into their word processing program. It doesn't have to be the latest version of the file format, just as long as it can be ingested and manipulated.
It doesn't make a difference how the person maintains the master file, just as long as they are able to produce one in the file type that satisfies the requirements of the HR system. I use word as my master file, and then produce a text or PDF version when it is needed.