TickSize - clarification on changing ticksize

content/reference-transaction-format.md

@@ -591,6 +591,8 @@ The `TickSize` value truncates the number of _significant digits_ in the exchang
 
 The `TickSize` does not affect the portion of an Offer that can be executed immediately. (For that reason, OfferCreate transactions with `tfImmediateOrCancel` are unaffected by `TickSize` values.) If the Offer cannot be fully executed, the transaction processing engine calculates the exchange rate and truncates it based on `TickSize`. Then, the engine rounds the remaining amount of the Offer from the "less important" side to match the truncated exchange rate. For a default OfferCreate transaction (a "buy" Offer), the `TakerGets` amount (the amount being bought) gets rounded. If the `tfSell` flag is enabled (a "sell" Offer) the `TakerPays` amount (the amount being sold) gets rounded.
 
+When an issuer enables, disables, or changes the `TickSize`, Offers that were placed under the previous setting are unaffected.
+
 
 ### Expiration ###
 

reference-transaction-format.html

@@ -986,6 +986,7 @@
 <p>When an Offer is placed into an order book, its exchange rate is truncated based on the <code>TickSize</code> values set by the issuers of the currencies involved in the Offer. When a trader offers to exchange XRP and an issued currency, the <code>TickSize</code> from the issuer of the currency applies. When a trader offers to exchange two issued currencies, the offer uses the smaller <code>TickSize</code> value (that is, the one with fewer significant digits). If neither currency has a <code>TickSize</code> set, the default behavior applies.</p>
 <p>The <code>TickSize</code> value truncates the number of <em>significant digits</em> in the exchange rate of an offer when it gets placed in an order book. Issuers can set <code>TickSize</code> to an integer from <code>3</code> to <code>15</code> using an <a href="#accountset">AccountSet transaction</a>. The exchange rate is represented as a number of significant digits plus an exponent; the <code>TickSize</code> does not affect the exponent. This allows the Ripple Consensus Ledger to represent exchange rates between assets that vary greatly in value (for example, a hyperinflated currency compared to a rare commodity). The lower the <code>TickSize</code> an issuer sets, the larger the increment traders must offer to be considered a higher exchange rate than the existing Offers.</p>
 <p>The <code>TickSize</code> does not affect the portion of an Offer that can be executed immediately. (For that reason, OfferCreate transactions with <code>tfImmediateOrCancel</code> are unaffected by <code>TickSize</code> values.) If the Offer cannot be fully executed, the transaction processing engine calculates the exchange rate and truncates it based on <code>TickSize</code>. Then, the engine rounds the remaining amount of the Offer from the "less important" side to match the truncated exchange rate. For a default OfferCreate transaction (a "buy" Offer), the <code>TakerGets</code> amount (the amount being bought) gets rounded. If the <code>tfSell</code> flag is enabled (a "sell" Offer) the <code>TakerPays</code> amount (the amount being sold) gets rounded.</p>
+<p>When an issuer enables, disables, or changes the <code>TickSize</code>, Offers that were placed under the previous setting are unaffected.</p>
 <h3 id="expiration">Expiration</h3>
 <p>Since transactions can take time to propagate and confirm, the timestamp of a ledger is used to determine offer validity. An offer only expires when its Expiration time is before the most-recently validated ledger. In other words, an offer with an <code>Expiration</code> field is still considered "active" if its expiration time is later than the timestamp of the most-recently validated ledger, regardless of what your local clock says.</p>
 <p>You can determine the final disposition of an offer with an <code>Expiration</code> as soon as you see a fully-validated ledger with a close time equal to or greater than the expiration time.</p>