diff --git a/SourceGen/RuntimeData/Help/editors.html b/SourceGen/RuntimeData/Help/editors.html
index 0f3ab8b..0221375 100644
--- a/SourceGen/RuntimeData/Help/editors.html
+++ b/SourceGen/RuntimeData/Help/editors.html
@@ -257,6 +257,27 @@ the .EQ directive.</p>
 operand references an address outside the scope of the data file.  Symbols
 marked as "constant" will not, though you can still specify them manually.</p>
 
+
+<h2><a name="lvtable">Edit Local Variable Table</a></h2>
+<p><a href="intro.html#local-vars">Local variables</a> are arranged in
+tables, which are created at a specific file offset.  They must be
+associated with a line of code, and are usually placed at the start of
+a subroutine.  The editor allows you to create, edit, delete, and
+move tables.</p>
+<p>Empty tables are allowed.  These can be useful if the "clear previous"
+flag is set.  If you want to delete the table, click the "Delete Table"
+button.</p>
+<p>Use the buttons to add, edit, or remove individual variables.  Each
+variable has a name, a value, a width, and an optional comment.  The
+standard naming rules for symbols apply.  Variables are only used for
+zero-page and stack-relative operands, so all values must fall in the
+range 0-255, with their width factored in.  So the maximum address for
+a two-byte pointer is $fe.</p>
+<p>You can move a table to any offset that is the start of an instruction
+and doesn't already have a local variable table present.  Click the
+"Move Table" button and enter the new offset in hex.  You can also use the
+up/down arrows to move to the next valid offset.</p>
+
 </div>
 
 <div id="footer">
diff --git a/SourceGen/RuntimeData/Help/index.html b/SourceGen/RuntimeData/Help/index.html
index 9fcd47c..4800098 100644
--- a/SourceGen/RuntimeData/Help/index.html
+++ b/SourceGen/RuntimeData/Help/index.html
@@ -35,6 +35,7 @@ and 65816 code.  The official web site is
     <li><a href="intro.html#sgconcepts">SourceGen Concepts</a></li>
     <li><a href="intro.html#about-symbols">All About Symbols</a>
       <ul>
+        <li><a href="intro.html#local-vars">Local Variables</a></li>
         <li><a href="intro.html#weak-refs">Weak References</a></li>
         <li><a href="intro.html#symbol-parts">Parts and Adjustments</a></li>
         <li><a href="intro.html#nearby-targets">Automatic Use of Nearby Targets</a></li>
@@ -71,11 +72,12 @@ and 65816 code.  The official web site is
     <li><a href="editors.html#flags">Edit Status Flags</a></li>
     <li><a href="editors.html#label">Edit Label</a></li>
     <li><a href="editors.html#operand">Edit Instruction Operand</a></li>
-    <li><a href="editors.html#data">Edit Data Format</a></li>
+    <li><a href="editors.html#data">Edit Data Operand</a></li>
     <li><a href="editors.html#comment">Edit Comment</a></li>
     <li><a href="editors.html#long-comment">Edit Long Comment</a></li>
     <li><a href="editors.html#note">Edit Note</a></li>
     <li><a href="editors.html#project-symbol">Edit Project Symbol</a></li>
+    <li><a href="editors.html#lvtable">Edit Local Variable Table</a></li>
   </ul></li>
 
   <li><a href="codegen.html">Code Generation &amp; Assembly</a>
diff --git a/SourceGen/RuntimeData/Help/intro.html b/SourceGen/RuntimeData/Help/intro.html
index 7716180..7fbf491 100644
--- a/SourceGen/RuntimeData/Help/intro.html
+++ b/SourceGen/RuntimeData/Help/intro.html
@@ -415,6 +415,19 @@ a double leading underscore (e.g. <code>__label</code>) for its own
 purposes.  In such cases, the label will be modified to comply with the
 target assembler syntax.</p>
 
+<p>Operands may use parts of symbols.  For example, if you have a label
+<code>MYSTRING</code>, you can write:</p>
+<pre>
+MYSTRING .STR    "hello"
+         LDA     #&lt;MYSTRING
+         STA     $00
+         LDA     #&gt;MYSTRING
+         STA     $01
+</pre>
+<p>See <a href="#symbol-parts">Parts and Adjustments</a> for more details.</p>
+
+<h4>Symbol Types</h4>
+
 <p><b>Platform symbols</b> are defined in platform symbol files.  These
 are named with a ".sym65" extension, and have a fairly straightforward
 name/value syntax.  Several files for popular platforms come with SourceGen
@@ -442,6 +455,10 @@ you to redefine symbols within a project.  (You can "hide" a platform
 symbol by creating a project symbol with the same name and an unused
 value, such as $ffffffff.)</p>
 
+<p><b>Local variables</b> are redefinable symbols that are organized
+into tables.  They're used to specify labels for zero-page and 65816
+stack-relative instructions.</p>
+
 <p><b>User labels</b> are labels added to instructions or data by the user.
 The editor won't allow you to add a label that conflicts, but if you
 manage to do so, the user label takes precedence over project and platform
@@ -457,19 +474,73 @@ that label.  Auto labels are only added where they are needed.  Because
 auto labels may be redefined or disappear, the editor will try to prevent
 you from referring to them when editing operands.</p>
 
-<p>Operands may use parts of symbols.  For example, if you have a label
-<code>MYSTRING</code>, you can write:</p>
+
+<h3><a name="local-vars">Local Variables</a></h3>
+
+<p>Local variables are applied to instructions that have zero
+page operands (<code>op ZP</code>, <code>op (ZP),Y</code>, etc.), or
+65816 stack relative operands
+(<code>op OFF,S</code> or <code>op (OFF,S),Y</code>).  While they must be
+unique relative to other kinds of labels, they don't have to be unique
+with respect to earlier variable definitions.  So you can define
+<code>TMP .EQ $10</code>, and a few lines later define
+<code>TMP .EQ $20</code>.  This is handy because zero-page addresses are
+often used in different ways by different parts of the program.  For
+example:</p>
+<pre>
+         LDA     ($00),Y
+         INC     $02
+         ... later ...
+         DEC     $00
+         STA     ($01),Y
+</pre>
+<p>If we had given <code>$00</code> the label <code>PTR</code> and
+<code>$02</code> the label <code>COUNT</code> globally,
+the second pair of instructions would look all wrong.  With local
+variable tables you can set <code>PTR=$00 COUNT=$02</code> for the first chunk,
+and <code>COUNT=$00 PTR=$01</code> for the second chunk.</p>
+
+<p>Local variables have a value and a width.  If we create a pair of
+variable definitions like this:</p>
+<pre>
+PTR      .eq     $00        ;2 bytes
+COUNT    .eq     $02        ;1 byte
+</pre>
+<p>Then this:</p>
 <pre>
-MYSTRING .STR    "hello"
-         LDA     #&lt;MYSTRING
          STA     $00
-         lda     #&gt;MYSTRING
-         STA     $01
+         STX     $01
+         LDY     $02
+</pre>
+<p>Would become:</p>
+<pre>
+         STA     PTR
+         STX     PTR+1
+         LDY     COUNT
 </pre>
 
-<p>The format editor allows you to choose which part of the symbol's
-value to use.  If the value doesn't match exactly, an adjustment will
-be applied.</p>
+<p>The scope of a variable definition starts at the point where it is
+defined, and stops when its definition is erased.  There are three
+ways for a table to erase an earlier definition:</p>
+<ol>
+  <li>Create a new definition with the same name.</li>
+  <li>Create a new definition that has an overlapping value.  For
+    example, if you have a two-byte variable <code>PTR = $00</code>,
+    and define a one-byte variable <code>COUNT = $01</code>, the
+    definition for <code>PTR</code> will be cleared because its second
+    byte overlaps.</li>
+  <li>Tables have a "clear previous" flag that erases all previous
+    definitions.  This doesn't usually cause anything to be generated in the
+    assembly sources; instead, it just causes SourceGen to stop using
+    that label.</li>
+</ol>
+<p>As you might expect, you're not allowed to have duplicate labels or
+overlapping values in an individual table.</p>
+<p>Not all assemblers support redefinable variables.  In those cases,
+the symbol names will be modified to be unique (e.g. the second definition
+of <code>PTR</code> becomes <code>PTR_1</code>), and variables will have
+global scope.</p>
+
 
 <h3><a name="weak-refs">Weak References</a></h3>
 
@@ -700,10 +771,12 @@ absolute long load, and because it can make 65816 code easier to read.</p>
 
 <h2><a name="pseudo-ops">Data and Directive Pseudo-Opcodes</a></h2>
 
-<p>There are only three assembler directives that appear in the code list:</p>
+<p>There are only four assembler directives that appear in the code list:</p>
 <ul>
   <li>.EQ - defines a symbol's value.  These are generated automatically
     when an operand that matches a platform or project symbol is found.</li>
+  <li>.VAR - defines a local variable.  These are generated for
+    local variable tables.</li>
   <li>.ORG - changes the target address.</li>
   <li>.RWID - specifies the width of the accumulator and index registers
     (65816 only).  Note this doesn't change the actual width, just tells
diff --git a/SourceGen/RuntimeData/Help/mainwin.html b/SourceGen/RuntimeData/Help/mainwin.html
index b220c5a..38cbe47 100644
--- a/SourceGen/RuntimeData/Help/mainwin.html
+++ b/SourceGen/RuntimeData/Help/mainwin.html
@@ -79,6 +79,10 @@ most-recently-opened projects will be available.</p>
 sub-windows can be resized.  The window sizes and column widths are
 saved in the application settings file.</p>
 
+<p>A toolbar near the top of the screen has some shortcut buttons.
+If you hover your mouse over them, a tooltip with an explanation will
+appear.</p>
+
 
 <h3><a name="code-list">Code List</a></h3>
 
diff --git a/SourceGen/RuntimeData/Help/settings.html b/SourceGen/RuntimeData/Help/settings.html
index 045325e..1cfc1b4 100644
--- a/SourceGen/RuntimeData/Help/settings.html
+++ b/SourceGen/RuntimeData/Help/settings.html
@@ -156,10 +156,14 @@ Sometimes the rules allow expressions to be written simply, other times
 explicit grouping with parenthesis is required.  Select whichever style
 you are most comfortable with.</p>
 
+<p>If you would like your local variables to be shown with a prefix
+character, you can set one here.</p>
+
 <p>The "quick set" buttons configure the fields on this tab to match
 the conventions of the specified assembler.  Select your preferred assembler
 with the combox box, then click "set" to set the fields.  (64tass and
-ACME use the "common" expression style.)</p>
+ACME use the "common" expression style, cc65 and Merlin 32 have their
+own unique styles.)</p>
 
 
 <h3><a name="appset-pseudoop">Pseudo-Op</a></h3>