All rules

Spacing around Latin text is inconsistent

latin-spacingon by default (info)Japanese

A space between Japanese and Latin letters in some places and not others

Example

How to fix

Match the way the rest of the document does it. If the team has decided, write it in the style guide.

Why it matters

Whether to put a space between Japanese and Latin letters or digits is a choice either way. What reads badly is mixing both in one document, which suggests the difference means something. chaff does not decide which is right; it points at whichever the document uses less. Letters, the space before a digit and the space after one are counted separately, since spacing before a number but not before its counter is common. A unit after a number (3GB) counts with the number; a name that starts with a letter and ends in a digit (H30, EC2, Phase 1) counts with the letters. A code such as a phone number, a date or a version (073-489-5909, 2026-06-02, 1.0.0) is not a quantity and is not counted. Nor is a date or a time written with units (9月, 2026年, 令和8年, 10月1日, 3時, 10時5分), which is packed by convention; neither its inside nor the space before it (は 9月, 午後3時) counts. The same goes for a clock time written with a colon (13:30). Nor is the space beside an e-mail address or a URL (privacy@example.com で), which marks where the address ends, or beside a booking or model number (予約番号 MN-48215 を, 型番 SB-210 と), which sets the number off from the sentence. A length of time (3ヶ月, 3 時間, 5日で, 3年) is a quantity and counts. Neither is a number written as the label of a title or a note (a section number such as 3.1 before its title, a note number after ※, the numbers of notes listed one per line in sequence, numbers opening the items of a list that go up, a number written right after a word such as 問 or 図), a code with a part starting with 0 (102-0094), a postal code after 〒 (〒100-8916), or a hyphenated address number right after a city, ward or town (千代田区紀尾井町1-3), since the space after it separates the label from its title or the next item. Nor is the space before a floor or room number written after the name of a building (本社 5階 第2会議室), which separates the parts of a location. Nor is the space between names on a line of names alone (株式会社あおば電子 経営企画部 IR担当, 東京本社 PR室), when both sides are names of a department, an office, a role or a company, since it separates one name from the next. The same goes for the space after a division such as 第1節. Nor is the space beside a code of six digits or more written without separators (口座番号 3056172 を), around and inside a number plate (ひばり野 330 ね 48-15), or between the parts of a value after a label and a colon (所属：経済学部 経済学科 1年, 振込先：みなと銀行 普通 1234567), which separates the parts of the value. The same goes for the space between a short label and its value written as a pair on their own (最高速度 40km/h, （内線 3839）, - 定員 30名); in a sentence (定員 30名で行います) it counts. Nor is the spacing inside a title or a quotation in 「」 or 『』, or inside the text of a link, which is the source's, not the writer's. When both ways are used equally often there is no minority, so no place is singled out, and a one-to-one tie is not reported.

What it does not flag

Codes such as phone numbers, dates and version numbers (1.0.0), the spaces beside a booking or model number (MN-48215), dates and times with units (9月, 10時5分), the space after a time with AM or PM (9:30AM), the space before a floor or room number after the name of a building (本社 5階), the space between names on a line of names alone (経営企画部 IR担当), the spaces beside a code of six digits or more or a number plate, the space between the parts of a value after a label and a colon (所属：経済学科 1年), the space between a label and its value (Bronzeプラン 10万円 (税込)), the spaces around an English word joining Japanese phrases (名前 or メッセージ), the boundary before a suffix bound to a Latin word (PDF版, IT化), the boundary after a channel or handle name (#pj_oss-team, @sato), heading numbers, the space after an item number at the head of a line (一 JIS…), quotations, the text of links and a licence notice the publisher appends at the end (a short closing paragraph that names a licence and links to its terms) are not counted. Neither way is called right. When the less common way is more than a fifth of the places (and at least five), or both ways are used equally at two places or more each, it is reported once, as a document written two ways, rather than place by place. A one-to-one tie is not reported.

Turning it off or relaxing it

This page is built from the rule's definition file:packages/chaff/rules/latin-spacing.yaml