Help with Diminutives?

I'm writing a novel set during World War II in Russia, but I know little about naming or the language. I've gotten so far that Russians don't use full names with people they know or informally, but I'm having a difficult time figuring out who would use what diminutive.

My main character is Svetlana. Her nickname is Sveta but I know there are also other diminutives for her name like Svetushka, Svetka, Svetulya, or Svetukha. Which one would her brothers use? Her mother? Grandparents or other relatives? Or what about friends or boyfriend?

Also, what about the names Yuri or Nikolai? I know the diminutives for both are Yura and Kolya, but what other diminutives would be used for them? I've done a lot of research but I can only find so much information.

Светланка; Света; Светуля; Светуня; Светуся; Светуха; Светуша; Вета; Светка; Лана
Юра; Юраня; Юрася; Юраха; Юраша; Юреня; Юрченя; Юка; Юша
Николайка, Николаха, Николаша, Николя, Коля, Колюня, Колюся, Колюха, Колюша, Колян, Коляха, Коляша, Кока, Ника, Никаха, Никаша, Никуся, Никуша

A lot of variants, but only BOLD are used more often.

..., Светлаша, Юрик, Колька,...


To judge which one the relatives would choose sooner, it's desirable to know more about them, their characters, education, where they live etc.

They live on a farm near Stalingrad (where most of my story takes place, during the Battle of Stalingrad.) Mostly I'm interested in how her uncle, aunt, or grandmother would use for them. Nearly all of my characters are Communists, or at least not anti-Communist. Also, how would my characters address older males? I read somewhere that people don't use diminutives for men as much, so would I just use the full name? Thanks guys for your responses.

So, they are колхозники.
Светка-Колька-Юра should work.

People generally addressed someone of older age:

officially (to less known persons) as товарищ/гражданин Иванов, товарищ/гражданка Петрова
officially (to well known persons) as Иван Юрьевич, Светлана Павловна
unofficially as (family friend, for example) дядя Юра, тётя Света

Quote:

---

Originally Posted by shadycat16

Mostly I'm interested in how her uncle, aunt, or grandmother would use for them.

---

Света,Юра,Коля/Sveta,Yura,Kolya are "base level" for family usage.
Светка,Юрка,Колька/Svetka,Yurka,Kol'ka are just a little more familiar and should be used more in your setting.
Other forms are generally rare and used in exceptional conditions (tenderness, persiflage, anger).

Quote:

---

Originally Posted by shadycat16

Also, how would my characters address older males?

---

Inside familily - uncle/aunt/grandmother + "base level" (males and females).

Quote:

---

Originally Posted by Alex80

Светка,Юрка,Колька/Svetka,Yurka,Kol'ka are just a little more familiar and should be used more in your setting.

---

I thought that the -ka ending was used more for anger?

Quote:

---

Originally Posted by shadycat16

I thought that the -ka ending was used more for anger?

---

It depends on hierarchy and familiarity.
"Base level" is applicable inside family through all levels of hierarhy. It is unusual to refer to someone by full name without joke or anger. (intercontinental joke: if mom calls you by full name you know you are in deep shit).
It is mandatory to say hierarchy title (uncle/grandfather) if you speak to/about person with higher level. You should not call parents by name.
It is mandatoty to say hierarchy title if you speak about person with higher level with person with lower level and title should be represented from his point of view.
You should not use -ka about persons with higher level (relative to person you talking to).
You can use -ka to persons with your level or lower freely. It's just like "they are my level or lower".

However exceptions are everywhere. Some people can call children by full names if they prefer to do so (like "his name is beautiful, I like to call him in this way"). And so on.

Alright, thank you a lot. That's very helpful information.

What about the name Yegor? What would the "base level" for this name be?

Quote:

---

Originally Posted by shadycat16

What about the name Yegor? What would the "base level" for this name be?

---

Yegor can be "base level" itself. Yegorka-form exists. Also Gosha (Гоша) can be used as diminutive form of it. But I am not sure which form are preferable.