If the director of the immigration detention center, etc. finds it necessary for maintaining discipline and order at the immigration detention center, etc. or for any other reason, the director may have an official designated by the director inspect letters sent or received by detainees.
For the following letters, the inspection set forth in the preceding paragraph is to be conducted to the extent necessary to confirm that they fall under those letters; provided, however, that this does not apply to letters set forth in item (iv) if there are special circumstances that give grounds to find that they are likely to result in harm to discipline and order at the immigration detention center, etc.:
letters received from consular officers, etc.;
領事官等から受ける信書
letters received by a detainee from an organ of the national government or of a local government;
被収容者が国又は地方公共団体の機関から受ける信書
letters sent by a detainee to an organ of the national government or of a local government that conducts an investigation concerning measures taken by the director of the immigration detention center, etc. against the detainee or other treatment the detainee has received;
letters sent or received by a detainee to or from an attorney (including a legal professional corporation or a joint corporation of attorneys and registered foreign lawyers; the same applies in paragraph (2) of the following Article) performing the duties provided for in Article 3, paragraph (1) of the Attorney Act concerning measures taken by the director of the immigration detention center, etc. against the detainee or other treatment the detainee has received.
定義第二条第一項第十六号・法令全体に適用
入国者収容所又は第五十五条の三第一項の規定により設けられる収容場
わかりやすく言うと
入国者収容所と、地方出入国在留管理局に設けられる収容場をまとめた呼び方です。
略称規定第五十五条の五第一項・この章及び第八章の中だけ
入国者収容所長又は地方出入国在留管理局長（以下この章及び第八章において「入国者収容所長等」という。）は、法務省令で定めるところにより、被収容者に対し、知的、教育的及び娯楽的活動その他の活動について、援助を与えるように努めなければならない。
わかりやすく言うと
入国者収容所の所長と地方出入国在留管理局の局長をまとめた呼び方です。
略称規定第五十五条の五十六第一項・この節の中だけ
入国者収容所長等は、その指名する職員に、被収容者と次に掲げる者（以下この節において「領事官等」という。）以外の者との面会に立ち会わせ、又はその面会の状況を録音させ、若しくは録画させるものとする。
わかりやすく言うと
被収容者の国籍または市民権の属する国の領事官と、被収容者の訴訟代理人や弁護人である弁護士（依頼を受けてそうなろうとする弁護士を含みます）のことです。