That is technically correct. 
If I’m not mistaken, the legal basis for a resident visa for the purpose of joining family is Art. 13 of the 外國護照簽證條例施行細則 (Enforcement Rules for the Issuance of ROC Visas to Foreign-Passport Holders).
Foreign passport holder may apply for resident visas in order to: join family; pursed studies; undertake employment; invest; conduct missionary work; conduct official duties; participate in international exchange programs; and engage in other activities approved by MOFA or other relevant agencies at the central-government level.
Unless related approval is not required, the applicant shall submit documents issued by the competent authorities at the central-government level, or their authorized agencies, approving the purpose of the applicant’s visit to the ROC when applying for a resident visa.
申請居留簽證目的，包括依親、就學、應聘、受僱、投資、傳教弘法、執行公務、國際交流及經外交部核准或其他相關中央目的事業主管機關許可之活動。
申請前項所定簽證，應檢附中央目的事業主管機關或其授權機關核發之許可從事簽證目的活動之文件。但不須經許可者，不在此限。
BOCA has a page on “RESIDENT VISAS FOR FOREIGN SPOUSES OF R.O.C.(TAIWAN) CITIZENS HAVING HOUSEHOLD REGISTRATION”.
www.boca.gov.tw/ct.asp?xItem=6136&ctNode=778&mp=2
So when Forumosans discussing marriage with ROC-nationals-with-household-registration use the term JFRV or “joining family resident visa”, are they not referring to this type of visa?