diff --git a/builtin/interpret-trailers.c b/builtin/interpret-trailers.c
index f76841c5280..f674b5f4b9e 100644
--- a/builtin/interpret-trailers.c
+++ b/builtin/interpret-trailers.c
@@ -45,7 +45,7 @@ static int option_parse_if_missing(const struct option *opt,
 	return trailer_set_if_missing(opt->value, arg);
 }
 
-static void new_trailers_clear(struct list_head *trailers)
+static void free_new_trailers(struct list_head *trailers)
 {
 	struct list_head *pos, *tmp;
 	struct new_trailer_item *item;
@@ -64,7 +64,7 @@ static int option_parse_trailer(const struct option *opt,
 	struct new_trailer_item *item;
 
 	if (unset) {
-		new_trailers_clear(trailers);
+		free_new_trailers(trailers);
 		return 0;
 	}
 
@@ -237,7 +237,7 @@ int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)
 		interpret_trailers(&opts, &trailers, NULL);
 	}
 
-	new_trailers_clear(&trailers);
+	free_new_trailers(&trailers);
 
 	return 0;
 }
diff --git a/trailer.c b/trailer.c
index 49bf26e3211..3b8f0ba103c 100644
--- a/trailer.c
+++ b/trailer.c
@@ -33,7 +33,7 @@ struct trailer_block {
 	size_t trailer_nr;
 };
 
-struct conf_info {
+struct trailer_conf {
 	char *name;
 	char *key;
 	char *command;
@@ -43,7 +43,7 @@ struct conf_info {
 	enum trailer_if_missing if_missing;
 };
 
-static struct conf_info default_conf_info;
+static struct trailer_conf default_trailer_conf;
 
 struct trailer_item {
 	struct list_head list;
@@ -59,7 +59,7 @@ struct arg_item {
 	struct list_head list;
 	char *token;
 	char *value;
-	struct conf_info conf;
+	struct trailer_conf conf;
 };
 
 static LIST_HEAD(conf_head);
@@ -210,7 +210,7 @@ static int check_if_different(struct trailer_item *in_tok,
 	return 1;
 }
 
-static char *apply_command(struct conf_info *conf, const char *arg)
+static char *apply_command(struct trailer_conf *conf, const char *arg)
 {
 	struct strbuf cmd = STRBUF_INIT;
 	struct strbuf buf = STRBUF_INIT;
@@ -424,7 +424,8 @@ int trailer_set_if_missing(enum trailer_if_missing *item, const char *value)
 	return 0;
 }
 
-static void duplicate_conf(struct conf_info *dst, const struct conf_info *src)
+void duplicate_trailer_conf(struct trailer_conf *dst,
+			    const struct trailer_conf *src)
 {
 	*dst = *src;
 	dst->name = xstrdup_or_null(src->name);
@@ -447,7 +448,7 @@ static struct arg_item *get_conf_item(const char *name)
 
 	/* Item does not already exists, create it */
 	CALLOC_ARRAY(item, 1);
-	duplicate_conf(&item->conf, &default_conf_info);
+	duplicate_trailer_conf(&item->conf, &default_trailer_conf);
 	item->conf.name = xstrdup(name);
 
 	list_add_tail(&item->list, &conf_head);
@@ -482,17 +483,17 @@ static int git_trailer_default_config(const char *conf_key, const char *value,
 	variable_name = strrchr(trailer_item, '.');
 	if (!variable_name) {
 		if (!strcmp(trailer_item, "where")) {
-			if (trailer_set_where(&default_conf_info.where,
+			if (trailer_set_where(&default_trailer_conf.where,
 					      value) < 0)
 				warning(_("unknown value '%s' for key '%s'"),
 					value, conf_key);
 		} else if (!strcmp(trailer_item, "ifexists")) {
-			if (trailer_set_if_exists(&default_conf_info.if_exists,
+			if (trailer_set_if_exists(&default_trailer_conf.if_exists,
 						  value) < 0)
 				warning(_("unknown value '%s' for key '%s'"),
 					value, conf_key);
 		} else if (!strcmp(trailer_item, "ifmissing")) {
-			if (trailer_set_if_missing(&default_conf_info.if_missing,
+			if (trailer_set_if_missing(&default_trailer_conf.if_missing,
 						   value) < 0)
 				warning(_("unknown value '%s' for key '%s'"),
 					value, conf_key);
@@ -511,7 +512,7 @@ static int git_trailer_config(const char *conf_key, const char *value,
 {
 	const char *trailer_item, *variable_name;
 	struct arg_item *item;
-	struct conf_info *conf;
+	struct trailer_conf *conf;
 	char *name = NULL;
 	enum trailer_info_type type;
 	int i;
@@ -585,9 +586,9 @@ void trailer_config_init(void)
 		return;
 
 	/* Default config must be setup first */
-	default_conf_info.where = WHERE_END;
-	default_conf_info.if_exists = EXISTS_ADD_IF_DIFFERENT_NEIGHBOR;
-	default_conf_info.if_missing = MISSING_ADD;
+	default_trailer_conf.where = WHERE_END;
+	default_trailer_conf.if_exists = EXISTS_ADD_IF_DIFFERENT_NEIGHBOR;
+	default_trailer_conf.if_missing = MISSING_ADD;
 	git_config(git_trailer_default_config, NULL);
 	git_config(git_trailer_config, NULL);
 	configured = 1;
@@ -620,7 +621,7 @@ static int token_matches_item(const char *tok, struct arg_item *item, size_t tok
  * distinguished from the non-well-formed-line case (in which this function
  * returns -1) because some callers of this function need such a distinction.
  */
-static ssize_t find_separator(const char *line, const char *separators)
+ssize_t find_separator(const char *line, const char *separators)
 {
 	int whitespace_found = 0;
 	const char *c;
@@ -645,28 +646,28 @@ static ssize_t find_separator(const char *line, const char *separators)
  *
  * If separator_pos is -1, interpret the whole trailer as a token.
  */
-static void parse_trailer(struct strbuf *tok, struct strbuf *val,
-			 const struct conf_info **conf, const char *trailer,
-			 ssize_t separator_pos)
+void parse_trailer(const char *line, ssize_t separator_pos,
+		   struct strbuf *tok, struct strbuf *val,
+		   const struct trailer_conf **conf)
 {
 	struct arg_item *item;
 	size_t tok_len;
 	struct list_head *pos;
 
 	if (separator_pos != -1) {
-		strbuf_add(tok, trailer, separator_pos);
+		strbuf_add(tok, line, separator_pos);
 		strbuf_trim(tok);
-		strbuf_addstr(val, trailer + separator_pos + 1);
+		strbuf_addstr(val, line + separator_pos + 1);
 		strbuf_trim(val);
 	} else {
-		strbuf_addstr(tok, trailer);
+		strbuf_addstr(tok, line);
 		strbuf_trim(tok);
 	}
 
 	/* Lookup if the token matches something in the config */
 	tok_len = token_len_without_separator(tok->buf, tok->len);
 	if (conf)
-		*conf = &default_conf_info;
+		*conf = &default_trailer_conf;
 	list_for_each(pos, &conf_head) {
 		item = list_entry(pos, struct arg_item, list);
 		if (token_matches_item(tok->buf, item, tok_len)) {
@@ -690,14 +691,14 @@ static struct trailer_item *add_trailer_item(struct list_head *head, char *tok,
 	return new_item;
 }
 
-static void add_arg_item(struct list_head *arg_head, char *tok, char *val,
-			 const struct conf_info *conf,
-			 const struct new_trailer_item *new_trailer_item)
+void trailer_add_arg_item(struct list_head *arg_head, char *tok, char *val,
+			  const struct trailer_conf *conf,
+			  const struct new_trailer_item *new_trailer_item)
 {
 	struct arg_item *new_item = xcalloc(1, sizeof(*new_item));
 	new_item->token = tok;
 	new_item->value = val;
-	duplicate_conf(&new_item->conf, conf);
+	duplicate_trailer_conf(&new_item->conf, conf);
 	if (new_trailer_item) {
 		if (new_trailer_item->where != WHERE_DEFAULT)
 			new_item->conf.where = new_trailer_item->where;
@@ -718,10 +719,10 @@ void parse_trailers_from_config(struct list_head *config_head)
 	list_for_each(pos, &conf_head) {
 		item = list_entry(pos, struct arg_item, list);
 		if (item->conf.command)
-			add_arg_item(config_head,
-				     xstrdup(token_from_item(item, NULL)),
-				     xstrdup(""),
-				     &item->conf, NULL);
+			trailer_add_arg_item(config_head,
+					     xstrdup(token_from_item(item, NULL)),
+					     xstrdup(""),
+					     &item->conf, NULL);
 	}
 }
 
@@ -730,7 +731,7 @@ void parse_trailers_from_command_line_args(struct list_head *arg_head,
 {
 	struct strbuf tok = STRBUF_INIT;
 	struct strbuf val = STRBUF_INIT;
-	const struct conf_info *conf;
+	const struct trailer_conf *conf;
 	struct list_head *pos;
 
 	/*
@@ -753,12 +754,11 @@ void parse_trailers_from_command_line_args(struct list_head *arg_head,
 			      (int) sb.len, sb.buf);
 			strbuf_release(&sb);
 		} else {
-			parse_trailer(&tok, &val, &conf, tr->text,
-				      separator_pos);
-			add_arg_item(arg_head,
-				     strbuf_detach(&tok, NULL),
-				     strbuf_detach(&val, NULL),
-				     conf, tr);
+			parse_trailer(tr->text, separator_pos, &tok, &val, &conf);
+			trailer_add_arg_item(arg_head,
+					     strbuf_detach(&tok, NULL),
+					     strbuf_detach(&val, NULL),
+					     conf, tr);
 		}
 	}
 
@@ -1044,20 +1044,19 @@ struct trailer_block *parse_trailers(const struct process_trailer_options *opts,
 
 	for (i = 0; i < trailer_block->trailer_nr; i++) {
 		int separator_pos;
-		char *trailer = trailer_block->trailers[i];
-		if (trailer[0] == comment_line_char)
+		char *line = trailer_block->trailers[i];
+		if (line[0] == comment_line_char)
 			continue;
-		separator_pos = find_separator(trailer, separators);
+		separator_pos = find_separator(line, separators);
 		if (separator_pos >= 1) {
-			parse_trailer(&tok, &val, NULL, trailer,
-				      separator_pos);
+			parse_trailer(line, separator_pos, &tok, &val, NULL);
 			if (opts->unfold)
 				unfold_value(&val);
 			add_trailer_item(head,
 					 strbuf_detach(&tok, NULL),
 					 strbuf_detach(&val, NULL));
 		} else if (!opts->only_trailers) {
-			strbuf_addstr(&val, trailer);
+			strbuf_addstr(&val, line);
 			strbuf_strip_suffix(&val, "\n");
 			add_trailer_item(head,
 					 NULL,
@@ -1200,8 +1199,7 @@ int trailer_iterator_advance(struct trailer_iterator *iter)
 		iter->raw = line;
 		strbuf_reset(&iter->key);
 		strbuf_reset(&iter->val);
-		parse_trailer(&iter->key, &iter->val, NULL,
-			      line, separator_pos);
+		parse_trailer(line, separator_pos, &iter->key, &iter->val, NULL);
 		/* Always unfold values during iteration. */
 		unfold_value(&iter->val);
 		return 1;
diff --git a/trailer.h b/trailer.h
index 76e6d941a07..f80f8f7e63f 100644
--- a/trailer.h
+++ b/trailer.h
@@ -5,6 +5,7 @@
 #include "strbuf.h"
 
 struct trailer_block;
+struct trailer_conf;
 
 enum trailer_where {
 	WHERE_DEFAULT,
@@ -45,6 +46,12 @@ struct new_trailer_item {
 	enum trailer_if_missing if_missing;
 };
 
+void duplicate_trailer_conf(struct trailer_conf *dst,
+			    const struct trailer_conf *src);
+void trailer_add_arg_item(struct list_head *arg_head, char *tok, char *val,
+			  const struct trailer_conf *conf,
+			  const struct new_trailer_item *new_trailer_item);
+
 struct process_trailer_options {
 	int in_place;
 	int trim_empty;
@@ -70,6 +77,12 @@ void parse_trailers_from_command_line_args(struct list_head *arg_head,
 void process_trailers_lists(struct list_head *head,
 			    struct list_head *arg_head);
 
+ssize_t find_separator(const char *line, const char *separators);
+
+void parse_trailer(const char *line, ssize_t separator_pos,
+		   struct strbuf *tok, struct strbuf *val,
+		   const struct trailer_conf **);
+
 struct trailer_block *parse_trailers(const struct process_trailer_options *,
 				     const char *str,
 				     struct list_head *head);
