What is the tie over t͡s, i͡u and i͡a for?

It marks two Latin letters that stand for one Cyrillic letter. With it, t͡s is ц and ts is тс, so царь is t͡sarʹ and детство is detstvo, and reading the text back gives the same Cyrillic.

Can I drop the ties and marks?

You can delete them after copying, which gives a form such as Dostoevskii, but that text no longer converts back exactly: ia is read as иа, not я.

How do I enter ʹ, ʺ and the tie when converting back?

Paste text that already has them. A plain apostrophe and double quote are also read as ь and ъ, and a letter typed with a separate combining mark, such as i followed by a breve, is joined before conversion.

Is this the same as passport spelling?

No. Passports and visas use their own standard, so copy an official spelling from the document itself.

Library of Congress Russian Transliteration

Paste Russian and read it in the ALA-LC romanization used in American library catalogues. Most letters match everyday transliteration; the differences are й as ĭ, э as ė, ё as ë, the hard and soft signs as ʺ and ʹ, and a tie over the pairs that stand for one letter: ц is t͡s, ю is i͡u and я is i͡a. Фёдор Михайлович Достоевский comes out as Fëdor Mikhaĭlovich Dostoevskiĭ. Switch Direction to turn ALA-LC text back into Cyrillic.

DirectionSchemeDeterministic character transliteration, not translation or passport spelling.

Text

Fëdor Mikhaĭlovich Dostoevskiĭ. I͡Asnai͡a Poli͡ana. Detstvo, otrochestvo, i͡unostʹ.

Latin to Cyrillic reads the tie marks: t͡s is Ц while ts is ТС, and i͡a is Я while ia is ИА. Plain ' and " are read as Ь and Ъ. Punctuation and spaces pass through unchanged.

Library of Congress mapping

t͡s

shch

i͡u

i͡a

Common questions

What is the tie over t͡s, i͡u and i͡a for?: It marks two Latin letters that stand for one Cyrillic letter. With it, t͡s is ц and ts is тс, so царь is t͡sarʹ and детство is detstvo, and reading the text back gives the same Cyrillic.
Can I drop the ties and marks?: You can delete them after copying, which gives a form such as Dostoevskii, but that text no longer converts back exactly: ia is read as иа, not я.
How do I enter ʹ, ʺ and the tie when converting back?: Paste text that already has them. A plain apostrophe and double quote are also read as ь and ъ, and a letter typed with a separate combining mark, such as i followed by a breve, is joined before conversion.
Is this the same as passport spelling?: No. Passports and visas use their own standard, so copy an official spelling from the document itself.

Every conversion follows the printed table for the chosen scheme, plus the listed typing rules for Latin input. The simple table spells е and э both as e and reads ts back as ц, so check those letters; this page makes no passport-spelling claim.